function IsDigit(cCheck)
{
 return ((('0'<=cCheck) && (cCheck<='9'))||cCheck=='.');
 }
function CheckNum(charValue,alertValue,obj)
{
	for(var iIndex=0;iIndex<charValue.length;iIndex++)
	{
		var cCheck=charValue.charAt(iIndex);
		if(!IsDigit(cCheck))
		{
		alert(alertValue);
		obj.focus();
		return false;
		}
	}
}