function ExamplePopup (url,w,h) {
	window.open(url,'_blank','width='+w+',height='+h+',toolbar=no,location=no,status=no,menubar=no,resizable=yes,scrollbars=no');
}

function BackgroundSamplePopup (bg_map,place) {
	window.open('background_examples.cgi?bg_map='+bg_map+'&place='+place,'bg_ex','width=750,height=450,toolbar=no,location=no,status=no,menubar=no,resizable=yes,scrollbars=yes');
}

function HelpPopup (feature) {
	window.open('/help.html' + '#' + feature,'help','width=640,height=500,toolbar=no,location=no,status=no,menubar=no,resizable=yes,scrollbars=yes');
}

function FilePopup (url,windowname,w,h) {
	window.open(url,windowname,'width='+w+',height='+h+',toolbar=no,location=no,status=no,menubar=yes,resizable=yes,scrollbars=yes');
}

function ChangeFormTarget(theForm) {
	theForm.target = (theForm.new_window.checked) ? '_blank' : '_top';
}

function confirmRedirect(url,text) {
	if(confirm("Would you like to go to "+text+"?")){
		window.location = url;
	} else {
		return false;
	}
}
function confirmRedirectSubmit(url,text,formname) {
	if(confirm("Would you like to go to "+text+"?")){
		document.main.action = url;
		document.main.target = '_top';
		document.main.form.value = formname;
		document.getElementById('data_input').name='form.data';
		document.main.submit();
	} else {
		return false;
	}
}

function Track_Statistics_Warning() {
	alert ('WARNING: GPS altitude data is very inaccurate; therefore, the elevation gain/loss statistics that are calculated from your track data may be off by a considerable amount.  Choosing to have your elevations replaced by DEM data may help, but even that is not guaranteed to be 100% correct.');
}

function Validate_Data_Box(data_box) {
	if (data_box.value.match(/[a-z0-9]/i) && !data_box.value.match(/\b(lati?|latt?itude?|long?|lng|long?t?itude?|street|add?ress?e?1?|city|town|plaats|ville|state|province|nation|country|zip|zipcode|postal|post ?code|code ?postale?|airport)\b/i)) {
		if (confirm('You\'ve entered some text into the \'data\' box, but it doesn\'t appear to have a valid header row on it and may produce an error.  Continue anyway?')) {
			return true;
		} else {
			return false;
		}
	}
}

function FilterMapList(theForm) {
	var format = document.getElementById('format').value;
	var mapCount = theForm.bg_map.options.length;
	var defaultMap = [];
	for (i = 0; i < mapCount; i++) {
		// if (theForm.bg_map.options[i].value == 'landsat') { defaultMap['jpg'] = i; defaultMap['jpeg'] = i; defaultMap['png'] = i; defaultMap['svg'] = i; }
		if (theForm.bg_map.options[i].value == 'google_hybrid') { defaultMap['google'] = i; }
		else if (theForm.bg_map.options[i].value == 'yahoo_hybrid') { defaultMap['yahoo'] = i; }
	}
	for (j = 0; j < mapCount; j++) {
		var txt = theForm.bg_map.options[j].text;
		var val = theForm.bg_map.options[j].value;
		var last = txt.substring(txt.length-1,txt.length);
		if (!format) {
			ShowMenuItem(theForm.bg_map,j);
		} else if (format == 'google') {
			if (val.indexOf('google') > -1 || val.indexOf('modis_daily') > -1 || val == 'usgs_topo' || val == 'usgs_aerial' || val == 'bluemarble' || val == 'landsat' || val == 'nrcan_topo' || val == 'nrcan_topo_names' || val == 'natatlas_county_outlines') { ShowMenuItem(theForm.bg_map,j); }
			else { HideMenuItem(theForm.bg_map,j); }
		} else if (format.indexOf('yahoo') > -1) {
			if (val.indexOf('yahoo') > -1) { ShowMenuItem(theForm.bg_map,j); }
			else { HideMenuItem(theForm.bg_map,j); }
		} else if (format == 'googleearth') {
			if (j == 0) { ShowMenuItem(theForm.bg_map,j); }
			else { HideMenuItem(theForm.bg_map,j); }
			theForm.bg_map.selectedIndex = 0;
		} else if (format == 'svg') {
			if (val.indexOf('google') > -1 || val.indexOf('yahoo') > -1) { HideMenuItem(theForm.bg_map,j); }
			else { ShowMenuItem(theForm.bg_map,j); }	
		} else { // PNG or JPEG
			if (val.indexOf('_tiles') > -1 || val.indexOf('google') > -1 || val.indexOf('yahoo') > -1 || val == 'tiger') { HideMenuItem(theForm.bg_map,j); }
			else { ShowMenuItem(theForm.bg_map,j); }	
		}
	}
	if (!bg_map_changed && defaultMap[format] != null && theForm.bg_map.selectedIndex == 0) { theForm.bg_map.selectedIndex = defaultMap[format]; }
	if (theForm.bg_map.options[theForm.bg_map.selectedIndex].disabled) {
		if (format == 'google') { theForm.bg_map.selectedIndex = defaultMap['google']; }
		else if (format.indexOf('yahoo') > -1) { theForm.bg_map.selectedIndex = defaultMap['yahoo']; }
		else { theForm.bg_map.selectedIndex = defaultMap['normal']; }
	}
}

function CheckForDisabledMapSelection(theForm) {
	var defaultMap = [];
	for (i = 0; i < theForm.bg_map.options.length; i++) {
		if (theForm.bg_map.options[i].value == 'landsat') { defaultMap['svg'] = defaultMap['jpg'] = defaultMap['png'] = i; }
		else if (theForm.bg_map.options[i].value == 'google_hybrid') { defaultMap['google'] = i; }
		else if (theForm.bg_map.options[i].value == 'yahoo_hybrid') { defaultMap['yahoo'] = i; }
	}
	if (theForm.bg_map.options[theForm.bg_map.selectedIndex].disabled) {
		theForm.bg_map.selectedIndex = defaultMap[theForm.format.value];
	}
	if (theForm.bg_map.options[theForm.bg_map.selectedIndex].value.indexOf('google') > -1) {
		if (theForm.format.value != 'google') {
			theForm.bg_map.selectedIndex = defaultMap[theForm.format.value]
		}
	} else if (theForm.bg_map.options[theForm.bg_map.selectedIndex].value.indexOf('yahoo') > -1) {
		if (theForm.format.value.indexOf('yahoo') < 0) {
			theForm.bg_map.selectedIndex = defaultMap[theForm.format.value]
		}
	}
}

function HideMenuItem(theMenu,i) {
	theMenu.options[i].disabled = true; theMenu.options[i].style.display = 'none';
}
function ShowMenuItem(theMenu,i) {
	theMenu.options[i].disabled = false; theMenu.options[i].style.display = '';
}

function GPSBabel_FilterFormats(theForm,theMenu) {
	var type = '['+theForm.type.value.toUpperCase()+']';
	for (j = 0; j < theMenu.length; j++) {
		var txt = theMenu.options[j].text;
		if (txt.indexOf(type) > -1) {
			theMenu.options[j].disabled = false;
		} else {
			if (j == theMenu.selectedIndex) { theMenu.selectedIndex = 0; }
			theMenu.options[j].disabled = true;
		}
	}
}

function GPSBabel_ShowOptions(theMenu) {
	var code = theMenu.value;
	for (j = 0; j < (theMenu.length); j++) {
		var c = theMenu.options[j].value;
		if (c == code) {
			if (document.getElementById(c+':options')) { Show(c+':options'); }
		} else {
			if (document.getElementById(c+':options')) { Hide(c+':options'); }
		}
	}
}

function Show(ob) {
	if (document.getElementById) { document.getElementById(ob).style.display = ''; }
	else if (document.all) { document.all.ob.style.display = ''; }
	else { document.ob.style.display = ''; }
}

function Hide(ob) {
	if (document.getElementById) { document.getElementById(ob).style.display = 'none'; }
	else if (document.all) { document.all.ob.style.display = 'none'; }
	else { document.ob.style.display = 'none'; }
}
function Toggle(ob) {
	if (document.getElementById) { currentVisibility = document.getElementById(ob).style.display; }
	else if (document.all) { currentVisibility = document.all.ob.style.display; }
	else { currentVisibility = document.ob.style.display; }
	if (currentVisibility == 'none') { Show(ob); }
	else { Hide(ob); }
}
function getRadioByValue (radioButtonOrGroup,value) {
	if (!radioButtonOrGroup.length) { // single button
		if (radioButtonOrGroup.value == value) {
			return radioButtonOrGroup;
		} else {
			return null;
		}
	} else {
		for (var b = 0; b < radioButtonOrGroup.length; b++) {
			if (radioButtonOrGroup[b].value == value) {
				return radioButtonOrGroup[b];
			}
		}
		return null;
	}
}


bg_map_changed = false;