function validate_add_to_cart_single(form){
	var qty_value = form.f_Qty.value;
	
	if(qty_value == ''){
		alert('ERROR ! \n\n- Please fill in the QTY\n')
		qty_value = ""
		form.f_Qty.focus()
		return false;
		
	} else {
		var numberFilter=/^[0-9]{1,10}$/i
		if( !(numberFilter.test(qty_value) && qty_value > 0 )){
			alert('ERROR ! \n\n- QTY must be postive integer\n')
			qty_value = ""
			form.f_Qty.focus();
			return false;
			
		} else {
			
			return true
		}//end of second check
	}//end of first check
}