function setUri(para, val) {      var strNewUrl = new String();      var strUrl = new String();      var url = window.location.href;      strUrl = window.location.href;      if (strUrl.indexOf("?") != -1) {        strUrl = strUrl.substr(strUrl.indexOf("?") + 1);  //獲取參數(shù)        if (strUrl.toLowerCase().indexOf(para.toLowerCase()) == -1) { //如果沒有找到參數(shù),則直接賦值          strNewUrl = url + "&" + para + "=" + val;          window.location.href = strNewUrl;        } else {          var aParam = strUrl.split("&");          for (var i = 0; i < aParam.length; i++) {            if (aParam[i].substr(0, aParam[i].indexOf("=")).toLowerCase() == para.toLowerCase()) {              aParam[i] = aParam[i].substr(0, aParam[i].indexOf("=")) + "=" + val;            }          }          strNewUrl = url.substr(0, url.indexOf("?") + 1) + aParam.join("&");          window.location.href = strNewUrl;        }      } else {        strUrl += "?" + para + "=" + val;        window.location.href = strUrl;      }    }

  //使用正則    function setPara(para, val) {      var newpar = "";      var url = window.location.href;      var pars = location.search.substring(1);      var reg = new RegExp("(^|)" + para + "=([^&]*)(|$)");      if (reg.test(pars)) {  //有需要的參數(shù)para        var p1 = pars.split(para)[0];  //productID=100857&count=1&        var p2 = pars.split(para)[1];  //=75825&coupval=1.5&addressID=358&invoiceID=1245&invoiceName=jesse        if (p2.indexOf("&") > -1) {          var p3 = p2.split("&")[0];          if (p3 == "=" + val + "") {            return false;          }          newpar = p1 + para + '=' + val + '&' + (p2.split(p3))[1];        } else {          if (p1) {            newpar = p1 + para + '=' + val;          } else {            newpar = para + '=' + val;          }        }      } else {        if (url.indexOf("?") == -1) {          newpar = pars +"&"+ para + "=" + val;        } else {          newpar = pars + "&" + para + "=" + val;        }      }      window.location.href = location.href.split('?')[0] + "?" + newpar;    }

<script>window.onload = function () {      var btn = document.getElementById("btnClick");      btn.onclick = function () {　　　　　　　　　　// url地址:http://localhost:54714/testuri.aspx?productID=100857&count=1&coupresId=12785&coupval=1.5&openId=12456&addressID=358&invoiceID=&invoiceName=　　　　　　　　　 //setUri("coupresId", 0);　　　　　　　　　　setPara("coupresId", 0); 　　　　} 　　}</script><input type="button" id="btnClick" value="重定義參數(shù)" />