在表单中验证电话号码…真的卡住了

Before you start flaming or anything at all, READ THIS! I have a regular expression verifying the format of a phone number entered in a form is correct. NOW what I am hoping to find is IF someone knows a way to verify if that number exists...so if the number doesnt exist and the user enters it, user will get an error message phone number does not exist and they will be prompted to enter a WORKINg phone number....Before you start flaming or anything at all, RE