How can I write a program that will take a phone number entered on my site and then call that number?

How can I write a program that when my site user enters a number into an input box, it will automatically be sent to an internet phone company like skype and then call that number? This is kinda like google maps call option, but without the third party number. I figure google goes through some sort of conference call option that involves cooperation with the phone companies? I need someone smart to help me with this. Thanks!!!