Recently, some javascript code has been written in the project, and the level needs to be improved _ javascript skills

Recently, some js functions have been written in the project, and the level needs to be improved. The Code is as follows:

Function ResumeError (){
Return true;
}
Window. onerror = ResumeError;

Function showdd (obj ){
Var dds = document. getElementById (obj). getElementsByTagName ("dd ");
Var len = dds. length;
If (dds [0]. style. display = "none "){
// This operation is an expanded menu. You need to determine whether this option exists in the cookie.
// 1. Yes, delete
// 2. None. do not perform the operation
Changeshowmenu (obj );
For (var I = 0; I <len; I ++ ){
Dds [I]. style. display = "";
}
} Else {
// This operation is a hidden menu. You need to determine whether this option exists in the cookie:
// 1. Yes. No operation is performed.
// 2. If no, add it to the end
Changehidemenu (obj );
For (var I = 0; I <len; I ++ ){
Dds [I]. style. display = "none ";
}
}
}

Function changeshowmenu (obj ){
Var temp = getcookie ("openid ");
If (temp. indexOf (obj )! = "-1 "){
Temp = temp. replace (obj + ",","")
Addcookie ("openid", temp, 24 );
}
}

Function changehidemenu (obj ){
Var temp = getcookie ("openid ");
If (temp. indexOf (obj) = "-1 "){
Addcookie ("openid", temp + obj + ",", 24 );
}
}


Function getcookie (sName) {// get cookie
Var aCookie = document. cookie. split (";");
For (var j = 0; j <aCookie. length; j ++ ){
Var aCrumb = aCookie [j]. split ("= ");
If (sName = aCrumb [0])
Return aCrumb [1];
}
Return null;
}

Function addcookie (objName, objValue, objHours) {// Add cookie
Var str = objName + "=" + objValue;
If (objHours> 0) {// when the value is 0, no expiration time is set. When the browser is disabled, the cookie disappears automatically.
Var date = new Date ();
Var MS = objHours x 3600*1000;
Date. setTime (date. getTime () + MS );
Str + = "; expires =" + date. toGMTString ();
}
Document. cookie = str;
}

// Based on a string separated by commas (,), which of the initialization menus need to be hidden?
Function initmenu (obj ){
Var arrmenu = obj. split (",");
For (var I = 0; I <arrmenu. length; I ++ ){
Var dds = document. getElementById (arrmenu [I]). getElementsByTagName ("dd ");
For (var j = 0; j <dds. length; j ++ ){
Dds [j]. style. display = "none ";
}
}
}

Function $ (obj ){
Return document. getElementById (obj );
}

Function delIt (){
Var cbxBool = 0;
For (var I = 0; I <cbxArray. length; I ++ ){
Var obj = $ (cbxArray [I]);
If (obj. checked = true ){
CbxBool = 1;
Break;
}
}

If (cbxBool = 1 ){
Var result = confirm ("the operation cannot be recovered. Are you sure you want to perform the current operation? ");
If (result ){
Return true;
}
} Else {
Alert ("You have not selected ");
Return false;
}
Return false;

}
Window. onload = function (){
Var lendl = document. getElementById ("globalLeft"). getElementsByTagName ("dl"). length;
If (getcookie ("openid") = null ){
Addcookie ("openid", "dl_c, dl_d, dl_e, dl_f, dl_g, dl_h, dl_ I, dl_j,", 24 );
}
Initmenu (getcookie ("openid "));



Var otable = document. getElementById ("table ");
Var trs = otable. getElementsByTagName ("tr ");
For (var I = 0; I <trs. length; I ++ ){
Trs [I]. onmouseover = function (){
This. style. backgroundColor = "# F7F7F7 ";
}
Trs [I]. onmouseout = function (){
This. style. backgroundColor = "# FFFFFF ";
}
}
}