// Function to restrict input to numeric characters only
function restrictChar(e, charType)
{
/*
ARGUMENTS:
event
  Required. Event to handle.
charType
  Required. Numeric expression that represents the character type to restrict.
  See Settings section for values.
  
SETTINGS
  The charType argument can have the following values:
  Setting	Description
     0		Numeric Characters 0-9
     1		Alpha Characters A-Z
*/
	var key;
	var keyChar;
	var reg;
	
	if (window.event)
	{
		// IE (e.keyCode or window.event.keyCode can be used)
		key = e.keyCode; 
	}
	else if (e.which)
	{
		// Mozilla
		key = e.which; 
	}
	else
	{
		// no event
		return true;
	}
	keyChar = String.fromCharCode(key);
	
	switch (charType)
	{
		case 0:
			reg = /\d/;
			break;
		case 1:
			reg = /\D/;
			break;
		default:
			// invalid argument
			return true;
	}
	return !reg.test(keyChar);
}