jquery ajax怎么动态获取url

<script type="text/javascript"> 
function getUrlPara(paraName){  
var sUrl  =  location.href; 
var sReg  =  "(?:\\?|&){1}"+paraName+"=([^&]*)" 
var re=new RegExp(sReg,"gi"); 
re.exec(sUrl); 
return RegExp.$1; 
} 
//应用实例：test_para.html?a=11&b=22&c=33 
alert(getUrlPara("a")); 
alert(getUrlPara("b")); 
</script>