Recently one of my colleague had a requirement like on clicking a control should disable the other. As per the requirement he is having a drop-down and two text boxes on the form. As per the requirement on clicking drop-down should disable the two text-boxes and again on clicking the disabled text-box should enable the text-box and disable the drop-down. But as per i known onclick event will not fire when the control is in disable state, i achieved this using DIV.
Download the attachment and let me know if any issues..
Happy Coding...