How to get value for a input button using jquery?

Like any other input, to get the value of a button use .val():

$('input:button').click(function() {
    alert($(this).val());
});​

http://jsfiddle.net/3QDM5/

I'm not sure exactly what you're trying to do with your script though!

use attr http://api.jquery.com/attr/

$(document).ready(function() { 
    $('#button1').click(function() { 
        var text = $(this).attr('value'); 
        $("#input").val(text); 
    }); 
});