//防止后退返回页面,如果非文本框、密码框、文本域控件，或控件非可用装填，则禁用后退按键
var ua=navigator.userAgent.toLowerCase(); 
var isIE=ua.indexOf("msie")>-1;
window.document.onkeydown =function(e){
    var e = e;
    var obj;        //事件源
    var t;            //控件类型
    var keyCode;    //按键ascii码
    if(isIE){
        e = event || window.event;
        keyCode = e.keyCode;
    }else{
        keyCode = e.keyCode || e.which;
        if(keyCode==undefined||keyCode==null||keyCode==‘‘){
            keyCode=String.fromCharCode(e.charCode);
        }
    }
    obj = e.target || e.srcElement; //获取事件源 
    t = obj.type || obj.getAttribute(‘type‘); 
    if (e.keyCode==8 && (obj.readOnly || obj.disabled || (t != "password" && t != "text" && t != "textarea" && obj.tagName!==‘INPUT‘))) {
        return false;
    }
};

// 获取参数
function getUrlParam(name) {
    var urlArr = [],urlObj={};
    name = decodeURI(name);
    urlArr=name.substring(1).split(‘&‘);
    for(var i =0;i<urlArr.length;i++){
        var valueArr=urlArr[i].split(‘=‘);
        urlObj[valueArr[0]]=valueArr[1];
    }
    return urlObj;
}