问如何在javascript中用<comma>替换%2C？

EN

 #&q=car&category=Car%20Audio%2CAccessories&brand=

function insertParam(key, value)
{
key = escape(key); value = escape(value);

var kvp = document.location.hash.substr(1).split('&');

var i=kvp.length; var x; while(i--) 
{
    x = kvp[i].split('=');

    if (x[0]==key)
    {
            x[1] = value;
            kvp[i] = x.join('=');
            break;
    }
}

if(i<0) {kvp[kvp.length] = [key,value].join('=');}

//this will reload the page, it's likely better to store this until finished

document.location.hash = kvp.join('&'); 
}

    insertParam("category",xy);
    insertParam("brand",zy);