jquery on change enable button code example
Example 1: How disable button jquery
$( "button" ).prop( "disabled", true );
Example 2: jquery enable submit button
//jQuery 1.6+ use:
$("#submitButtonID").prop('disabled', true); //disable
$("#submitButtonID").prop('disabled', false); //enable
//jQuery 1.5 and below use:
$("#submitButtonID").attr('disabled','disabled'); //disable
$("#submitButtonID").removeAttr('disabled'); //enable