function IsEmptyString(pstr) {

	var blnRet = true;
	for (i = 0; i < pstr.length; i++) {
		character = pstr.charAt(i);
		if (!(character == " " || character == "\f" || character == "\n" || character == "\r" || character == "\t" || character == "\v")) {
			blnRet = false;
			break;
		}
	}
	return blnRet;
}

function IsNumber(thisInt) {
	thisInt = parseInt(thisInt);

	if (isNaN(thisInt)) {
		return false;
	}

	return true;
}

function IsValidEmail(str) {
	// are regular expressions supported?
	var supported = 0;
	if (window.RegExp) {
		var tempStr = "a";
		var tempReg = new RegExp(tempStr);
		if (tempReg.test(tempStr)) supported = 1;
	}
	if (!supported)
		return (str.indexOf(".") > 2) && (str.indexOf("@") > 0);
	var r1 = new RegExp("(@.*@)|(\\.\\.)|(@\\.)|(^\\.)");
	var r2 = new RegExp("^.+\\@(\\[?)[a-zA-Z0-9\\-\\.]+\\.([a-zA-Z]{2,3}|[0-9]{1,3})(\\]?)$");
	return (!r1.test(str) && r2.test(str));
}

function IsRadioChecked(thisRadio) {
	for (var i = 0; i < thisRadio.length; i++) {
		if (thisRadio[i].checked) {
			return true;
		}
	}

	return false;
}

function hideLayer (layername) {

	// Check browser support for layers
	ns4 = (document.layers)? true:false
	ie4 = (document.all)? true:false

	if (ie4) {
		document.all(layername).style.visibility = 'hidden';
	} else if (ns4) {
		document.layers[layername].visibility = 'hide';
	} else {
		document.getElementById(layername).style.visibility = 'hidden';
	}

}