Div pop-up logon window

<Meta charset = "UTF-8"/> <SCRIPT type = "text/JavaScript"> // pop-up login function showno () // hide two layers {document. getelementbyid ("doing "). style. display = "NONE"; document. getelementbyid ("divlogin "). style. display = "NONE";} function $ (ID) {return (document. getelementbyid )? Document. getelementbyid (ID): Document. all [ID];} function showfloat () // display two layers based on the screen size {var range = getrange (); $ ('doing '). style. width = range. width + "PX"; $ ('doing '). style. height = range. height + "PX"; $ ('doing '). style. display = "Block"; document. getelementbyid ("divlogin "). style. display = "";} function getrange () // obtain the screen size {var Top = document. body. scrolltop; var left = document. body. scrollleft; Var Height = document. body. clientheight; var width = document. body. clientwidth; If (Top = 0 & left = 0 & Height = 0 & width = 0) {Top = document.doc umentelement. scrolltop; left = document.doc umentelement. scrollleft; Height = document.doc umentelement. clientheight; width = document.doc umentelement. clientwidth;} return {top: Top, left: Left, height: height, width: width };}// this is a self-written logon method, If you want to use this function, modify login () {var username = document. getelementbyid ("txtusername "). value; var Pwd = document. getelementbyid ("txtpwd "). value; If (username = "" | Pwd = "") {alert ("Enter the user name or password"); return;} var DIV = document. getelementbyid ("userinfo"); var XMLHTTP = getxmlhttpobject (); // specify the callback function XMLHTTP. onreadystatechange = function () {If (XMLHTTP. readystate = 4 & XMLHTTP. status = 200 ){ M = XMLHTTP. responsetext; If (M = "0") {alert ("incorrect user name or password");} else {MSG = m; Div. innerhtml = "<a href = '.. /musicsite/membercenter. aspx 'target = '_ blank'> "+ M +" </a> "; Div. setattribute ("class", "mid"); showno () ;}}; // initialize xmlhttprequst XMLHTTP. open ("Post", "login. aspx ", true); // sets the header XMLHTTP. setRequestHeader ("Content-Type", "application/X-WWW-form-urlencoded"); // send data var DATA = "username =" + Escape (username) + "& Pwd =" + escape (PWD); XMLHTTP. Send (data) ;}</SCRIPT> <! -- The following is the code written in HTML --> <! -- This is your logon button --> <a href = "#" onclick = "showfloat ()"> logon </a> <! -- Pop-up logon ---> <! -- Add a translucent layer --> <Div id = "doing" style = "filter: alpha (opacity = 30);-moz-opacity: 0.3; opacity: 0.3; background-color: #000; width: 100%; Height: 100%; Z-index: 1000; position: absolute; left: 0; top: 0; display: none; overflow: hidden; "> </div> <! -- Add a logon layer --> <Div id = "divlogin" style = "border: solid 10px #898989; Background: # FFF; padding: 10px; width: 400px; z-index: 1001; Height: 200px; position: absolute; display: none; top: 50%; left: 50%; margin:-200px 0 0-200px; "> <Div style =" padding: 3px 15px 3px 15px; text-align: Left; Vertical-align: middle; "> <div> Username: <input type = "text" style = "border: 1px solid #898989; Height: 20px;" id = "txtusername"/> <br/> password: <input type = "password" style = "border: 1px solid #898989; Height: 20px; margin-left: 10px;" id = "txtpwd" onkeydown = "If (event. keycode = 13) {login () ;}"/> </div> <br/> <Div style = "text-align: center;"> & nbsp; & nbsp; <input type = "button" id = "bttlogin" value = "login" onclick = "login ();"/> & nbsp; <input type = "button" id = "bttcancel" value = "cancel" onclick = "showno ()"/> </div>