js-js截取url

function getHref(sArgName){
    var sHref = window.location.href;
    var args = sHref.split("?");
    var retval = ""; 
    if(args[0] == sHref){ 
        return retval; 
    }
    var str = args[1]; 
    args = str.split("&"); 
    for(var i = 0; i < args.length; i++ ){ 
        str = args[i]; 
        var arg = str.split("="); 
        if(arg.length <= 1) continue; 
        if(arg[0] == sArgName) retval = arg[1]; 
    } 
    return retval;
}

getHref("key")