从url获取指定参数值，获取当前url上下文

1.从url获取指定参数值

function requestParam(paras){
var url = location.href;
var paraString = url.substring(url.indexOf("?")+1,url.length).split("&");
var paraObj = {};
for (i=0; j=paraString[i]; i++){
paraObj[j.substring(0,j.indexOf("=")).toLowerCase()] = j.substring(j.indexOf("=")+1,j.length);
}
var returnValue = paraObj[paras.toLowerCase()];
if(typeof(returnValue)=="undefined"){
return "";
}else{
return returnValue;
}
}
2.获取url上下文
function getContext() {
var url = window.location.href;
var ret = "/";
if (url.indexOf("http://") != -1) {
var hoststr = url.substr(7, url.length - 7);
var index = hoststr.indexOf("/");
if (index > 0) {
var context = hoststr.substr(index + 1, hoststr.length - (index + 1));
index = context.indexOf("/");

if (index < 0) {
ret += context;
} else {
context = context.substring(0, index);
ret += context;
}
}
ret = "http://" + hoststr.substring(0, hoststr.indexOf("/")) + ret;
}
return ret;
}//返回值类似：http://171.14.14.118:9494/itemss