var objVisibleLayer;

function showLayer(layerID){
	if( objVisibleLayer ){
		if( objVisibleLayer.id == layerID ) return 0;
	}

	objVisibleLayer = document.getElementById(layerID);

	if( objVisibleLayer )
		objVisibleLayer.style.display = '';

}

function hideLayer(){

	if( objVisibleLayer ){
		objVisibleLayer.style.display = 'none';
		objVisibleLayer = null;
	}

}

function swapSideImage(imgName, imgPath){
	var imgRef = document.getElementById(imgName);

	if( imgRef ){

		imgRef.src = imgPath;

	}

}

function trim(str)
{
   return str.replace(/^\s*|\s*$/g,"");
}

function isEmail(email) {
	var invalidCharString = " ,<>!\"?%^&*()+=*/\\\';:#~[]{}";
	var i = 0;
	
	for (i = 0; i < invalidCharString.length; i++) {
		if (-1 < email.indexOf(invalidCharString.charAt(i))) {
			return false;
		}
	}
	
	var firstAt = email.indexOf('@');
	var lastAt = email.lastIndexOf('@');
	var lastDot = email.lastIndexOf('.');
	if (!((0 < firstAt) && (1 < lastDot) && (firstAt == lastAt) && ((firstAt + 1) < lastDot) && (lastDot < (email.length - 2)))) 
	{
		return false;
	}
	else {
		return true;
	}
}

function DaysArray(n) {
	for (var i = 1; i <= n; i++) {
		this[i] = 31
		if (i==4 || i==6 || i==9 || i==11) {this[i] = 30}
		if (i==2) {this[i] = 29}
   } 
   return this
}

function isDate(dtStr){
var dtCh= "/";
var minYear=1900;
var maxYear=2100;
	var daysInMonth = DaysArray(12);
	var pos1=dtStr.indexOf(dtCh);
	var pos2=dtStr.indexOf(dtCh,pos1+1);
	var strDay=dtStr.substring(0,pos1);
	var strMonth=dtStr.substring(pos1+1,pos2);
	var strYear=dtStr.substring(pos2+1);
	strYr=strYear;
	if (strDay.charAt(0)=="0" && strDay.length>1) strDay=strDay.substring(1);
	if (strMonth.charAt(0)=="0" && strMonth.length>1) strMonth=strMonth.substring(1);
	for (var i = 1; i <= 3; i++) {
		if (strYr.charAt(0)=="0" && strYr.length>1) strYr=strYr.substring(1);
	}
	month=parseInt(strMonth);
	day=parseInt(strDay);
	year=parseInt(strYr);
	if (pos1==-1 || pos2==-1){
		return false;
	}
	if (strMonth.length<1 || month<1 || month>12){
		
		return false;
	}
	if (strDay.length<1 || day<1 || day>31 || (month==2 && day>daysInFebruary(year)) || day > daysInMonth[month]){
		
		return false;
	}
	if (strYear.length != 4 || year==0 || year<minYear || year>maxYear){
		
		return false;
	}
	if (dtStr.indexOf(dtCh,pos2+1)!=-1 || isInteger(stripCharsInBag(dtStr, dtCh))==false){
		
		return false;
	}
return true;
}
function stripCharsInBag(s, bag){
	var i;
    var returnString = "";
    // Search through string's characters one by one.
    // If character is not in bag, append to returnString.
    for (i = 0; i < s.length; i++){   
        var c = s.charAt(i);
        if (bag.indexOf(c) == -1) returnString += c;
    }
    return returnString;
}

function daysInFebruary (year){
	// February has 29 days in any year evenly divisible by four,
    // EXCEPT for centurial years which are not also divisible by 400.
    return (((year % 4 == 0) && ( (!(year % 100 == 0)) || (year % 400 == 0))) ? 29 : 28 );
}

function isInteger(s){
	var i;
    for (i = 0; i < s.length; i++){   
        // Check that current character is number.
        var c = s.charAt(i);
        if (((c < "0") || (c > "9"))) return false;
    }
    // All characters are numbers.
    return true;
}

function SetVisibility(id, visible) {
	var identity=document.getElementById(id);
	if (visible) {
		identity.className = "visibleElement";
	}
	else {
		identity.className = "hiddenElement";
	}
}

function getInputArrayValue(inputArray) {
	var value = '';
	
	if (!inputArray.length) {
		// Only one radio button, so form.radiobuttonname returns a radiobutton element, not an array
		if (inputArray.checked) {
			value = inputArray.value;
		}
	}
	else {
		for (var i=0; i<inputArray.length; i++) {
			if (inputArray[i].checked) {
				value = inputArray[i].value;
				break;
			}
		}
	}
	
	return value;
}