Implement a simple sliding menu with php_PHP tutorial

<script><br> /**<br> * Generate the html code string of the menu <br> * The entry parameter is the category number that is opened by default in the menu <br>*/<br> function menu(n) {<br> ​this.ar = new Array(<br> /**<br> * Parameter array<br> * Column 1: Category <br> * Column 2: Subcategory <br> * Column 3: Title <br> ​​*/<br> ​new Array(1,0,"Major Category One"),<br> ​new Array(1,1,"Small Class 1"),<br> ​new Array(1,2,"Small Category 2"),<br> ​new Array(2,0,"Major Category 2"),<br> ​new Array(2,1,"Small Class 1"),<br> ​new Array(2,2,"Small Category 2"),<br> new Array(2,3,"Small Category Three"),<br> ​new Array(3,0,"Major Category Three"),<br> ​new Array(3,1,"Small Category One"),<br> ​new Array(3,2,"Small Category 2"),<br> ​new Array(4,0,"Major Category Four"),<br> ​new Array(4,1,"Small Class 1"),<br> ​new Array(4,2,"Small Category 2"),<br> new Array(4,3,"Small Category Three")<br> );<br> ​this.width =120;<br> ​this.bgcolor = "#f0f0f0";<br> ​this.bordercolorlight = "#c0c0c0";<br> ​this.bordercolordark = "#FFFFFF";<br> ​this.tr_bgcolor = "#d0d0d0";<br> var s = "<table border=1 align=center width="+this.width+" bgcolor="+this.bgcolor+" bordercolorlight="+this.bordercolorlight+" bordercolordark="+this.bordercolordark+" CELLPADDING=0 CELLSPACING= 0>"<br> ​for(var i=0;i<this.ar.length;i++) { //Construct the html structure of the menu, in which the size class number is used as a custom parameter for use in event response. <br /> 　　if(this.ar[i][1] == 0) {<br /> 　　if(i > 0)<br> 　　　　s += "</table></td></tr>";<br> 　　 var vk = this.ar[i][0]==n?"block":"none";<br> s += "<tr id='pad' bgcolor="+this.tr_bgcolor+" v1="+this.ar[i][0]+" v2="+this.ar[i][1]+" ><td align=center>"+this.ar[i][2]+"</td></tr><tr style='display:"+vk+"'><td&gt ;<table width=100%>";<br> 　　}else<br> s += "<tr><td id='bar' v1="+this.ar[i][0]+" v2="+this.ar[i][1]+">"+ this.ar[i][2]+"</td></tr>";<br> }<br> s += "</table></td></tr></table>";<br> return s;<br> }<br> /*** Create menu ***/<br> menus.innerHTML = menu(4);<br> </script>