This is my HTML lt select name countries id countries MULTIPLE size 8 gt lt option value UK gt UK lt option gt lt option value US gt US lt option gt lt option value Canada gt Canada lt option gt lt option value France gt France lt option gt lt option value India gt India lt option gt lt option value China gt China lt option gt lt select gt lt br gt lt input type button id select all name select all value Select All gt When user click on Select All button I want all the options in the select box to be selected select all click function

How can I select all options of multi-select select box on click?

Try this:

$('#select_all').click(function() {
    $('#countries option').prop('selected', true);
});

And here's a live demo.

~ Answered on 2012-03-29 11:45:23