How to disable button without postback but still disable button after post back?

Greeting everyone, I'm August, the student developer.

My web application require disable the save button when the searching criteria changed and enable save button after the search button clicked.
The simple code as follow:

 .aspx
------------------------------------------------------------------------

         function disableBtn1(id) // Disable Save Button
        {
            obj = document.getElementById(id);
            obj.disabled = true;
        }
        function enableBtn1(id)
        {
            obj = document.getElementById(id);
&nbs ...