Javascript: Setting variable to work in attr line

Kinda of a noob question, can't seem to solve it, but I may just be tired.

What I'm trying to do is insert a PHP variable in to Javascript (Jquery), and then that variable in to an attr line.

The script I'm using to create the variable:

$.extend({
  getUrlVars: function(){
    var vars = [], hash;
    var hashes = window.location.href.slice(window.location.href.indexOf('?') + 1).split('&');
    for(var i = 0; i < hashes.length; i++)
    {
      hash = hashes[i].split('=');
      vars.push(hash[0]);
      vars[hash[0]] = hash[1];
    }
    return 开发者_运维知识库vars;
  },
  getUrlVar: function(name){
    return $.getUrlVars()[name];
  }
});

Setting the variable:

var searchresult =  $.getUrlVar('s');

And then, where I'm stuck, inserting the variable within the line so that'll come out correctly when I send it off to my iframe.

  $(function() {

  $("#searchbutton").click(function() {

     $("#theiframe").attr("src","http://whateverdomain.com/index.php?s=VARIABLE HERE WITHIN JAVASCRIPT");
  })

})

I know, kinda beginners question going here, but I admit it, I'm stuck.

$(function() {
    $("#searchbutton").click(function() {
        var searchresult = getUrlVar("s");
        $("#theiframe").attr("src", "http://example.com/index.php?s=" + searchresult);
    })
})

There's already a jQuery plugin that parses URL query parameters - really no need to write your own.* Check out the example page for parsing query parameters.

_{^*Though it looks like you didn't actually write the getUrlVars plugin yourself.}