Develop "click to call" software for website-phone

WE need an icon in our website that says "Press to call" we need that by Pressing the Button the customer "automatically" dials to our office and we can take the customer CALL directly from our website he is visiting in that moment something like this [login to view URL] Tell me if you can develop,,Customer presses button in website and the pressed button dials to our office phone,.. The phone dialed can be a normal phone or an ip phone...