how to get GET variable's value in javascript?

how can i get the get variable in javascript?

i want to pass it in jquery function.

function updateTabs(){

            //var number=$_GET['number']; how can i do this?
        alert(number);
        $( "#tabs" ).tabs({ selected: number });


    }

Answer

var $_GET = {};
if(document.location.toString().indexOf('?') !== -1) {
    var query = document.location
                   .toString()
                   // get the query string
                   .replace(/^.*?\?/, '')

                   // and remove any existing hash string (thanks, @vrijdenker)
                   .replace(/#.*$/, '')
                   .split('&');

    for(var i=0, l=query.length; i       var aux = decodeURIComponent(query[i]).split('=');
       $_GET[aux[0]] = aux[1];
    }
}
//get the 'index' query parameter

alert($_GET['index']);