isNull = function(val) {
	if(val == null){
		return true;
	} else {
		return false;
	}
}

isEmpty = function(valueString) {
   if ((valueString == null) || (valueString.length == 0)) {
      return true;
   }
   else { 
	   return false; 
   }
}

isNumber = function(val) {
   var validchars = "0123456789.";
   var isNumber = true;
   var c; 
   for (i = 0; i < val.length && isNumber == true; i++) { 
      c = val.charAt(i); 
      if (validchars.indexOf(c) == -1) {
         isNumber = false;
      }
   }
   return isNumber;
}

isValue = function(val) {
	if(isNull(val) || isEmpty(val)){
		return false;
	} else {
		return true;
	}
}