var botonChat;

function PopUpWindows(){
  windowChat();
}
function windowChat(){
  botonChat=document.getElementById('boton_chat');
  botonChat.onclick=chatWindow;
}
function chatWindow() {
window.open('http://www.creartgraphics.com/chat/chat.html', 'popup', 'width=431, height=321, top=100, left=100, menubar=0, scrollbars=false, location=0, toolbar=0,  resizable=1, status=0');
return false;
}