起点页面传值js,有空研究学习下

<script> 
function ChangeParam(name, value) { 
var url = window.location.href; 
var newUrl = ""; 
var reg = new RegExp("(^|)" + name + "=([^&]*)(|$)"); 
var tmp = name + "=" + value; 
if (url.match(reg) != null) { 
newUrl = url.replace(eval(reg), tmp); 
} 
else { 
if (url.match("[\?]")) { 
newUrl = url + "&" + tmp; 
} 
else { 
newUrl = url + "?" + tmp; 
} 
} 
//如果更换了类别,则从第1页开始 
if (name != "PageIndex") { 
reg = new RegExp("(^|)PageIndex=([^&]*)(|$)"); 
tmp = "PageIndex=1"; 
if (newUrl.match(reg) != null) { 
newUrl = newUrl.replace(eval(reg), tmp); 
} 
} 
location.href = newUrl; 
} 
function QueryMonthTicket() 
{ 
if($("selectM")!=null && $("selectY")!=null) 
{ 
var month=$("selectY").value+$("selectM").value; 
ChangeParam("Month",month); 
} 
} function GoPage() 
{ 
var page=$("txtPage").value.trim(); 
if(page.length===0){ 
alert("请您输入页码"); 
return false; 
}; 
var strNum = '1234567890'; 
var isNum = true; 
for(var i=0;i<page.length;i+=1){ 
var c = page.charAt(i); 
if(strNum.indexOf(c) < 0){ 
isNum = false; 
break; 
}; 
}; 
if(isNum){ 
if(parseInt(page)>parseInt(initTotalPage)){ 
alert("您输入的页数超过总页数，请重新输入！"); 
return false; 
}; 
ChangeParam("PageIndex",page); 
}else alert('您输入的信息有误，请重新输入！'); 
} 
function GoEnter(evt){ 
evt=evt||window.event; 
if(evt && evt.keyCode == 13) return GoPage(); 
}; 
</script>