String.prototype.isUpperCase = function() {
	
	for(i=0; i<this.length; i++)
	{
		c = this.charAt(i);
		if(c >= 'a' && c <= 'z')
		{
			//alert('a lower case char was found, returning false');
			return false;
		}
	}
	
	//alert('all characters are upper case, returning true');
	return true;
};