/**
 * Ensures that the passed value is a number (float or integer).
 * 
 * @param num  Number to be verified.
 * 
 * @return boolean True if number is valid.
 **/
function validateNumber(num)
{
	for (i = 0; i < num.length; i++)
	{
		// Check that current character is a number or a decimal point.
		var c = num.charAt(i);
		if (((c < "0") || (c > "9")) && c!=".") return false;
	}
	// All characters are numbers.
	return true;
}