Implementation of whack-a-mole game in JavaScript

<style>
    #div0{
     text-align: center;
     width: 1360px;
     height: 600px;
     margin: 60px auto;
     background-image: url("images/bg.jpg");
     position: relative;
    }
    #div_top{
     text-align: left;
     color:brown;
     width: 360px;
     height: 100px;
     position: absolute;
     left: 500px;
    }
    #div_left{
     width: 350px;
     height: 320px;
     position: absolute;
     left: 300px;
     top: 150px;
    }
    #tab_data{
     width:350px;
     height:320px;
    }
    #div_right{
     width: 350px;
     height: 320px;
     position: absolute;
     right: 380px;
     top: 150px;
    }
    #tab{
     width:320px;
     height:320px;
    }
    #tab td{
     background-image:url("images/00.jpg");
     background-repeat:no-repeat;
     background-position:center;
    }
</style>

<div id="div0">
   <div id="div_top">
     Game Instructions:<br/>
    Click the "Start Game" button, and a mouse will be randomly generated in the picture below. Click on the mouse to hit it before it disappears.<br/>
    You will get 100 points if you hit the mouse once, and 100 points will be deducted if you miss. Act quickly and test your reaction and eyesight! <br/>
   </div>
   <div id="div_left">
    <table id="tab_data">
     <tr>
      <th>Game time:</th>
      <td><input type="text" name="text_time" value="1" />minutes</td>
     </tr>
     <tr>
      <th>Countdown:</th>
      <td><input type="text" name="text_CD" value="60" disabled="disabled"/>seconds</td>
     </tr>
     <tr>
      <th>Occurs every:</th>
      <td><input type="text" name="text_hide" value="1" />seconds</td>
     </tr>
     <tr>
      <th>Dwell time:</th>
      <td><input type="text" name="text_show" value="1" />seconds</td>
     </tr>
     <tr>
      <th>Score:</th>
      <td><span id="span_score"></span></td>
     </tr>
     <tr>
      <th colspan="2">
       <input type="button" value="Start the game" id="but_start"/>
       &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
       <input type="button" value="End Game" id="but_end"/>
      </th>
     </tr>
    </table>
   </div>
   <div id="div_right">
    
   </div>
</div>

<script>
   var collTd=[];//Record all td
   var oTdMouse; //Record the selected td
   //Define the label elements in the variable record page var oButStart, oButEnd;
   var oTextTime,oTextHide,oTimeShow,oTimeCD;
   var oSpanScore;
   //Define variables to record time parameters:
   var iAll,iCD,iShow,iHide,iCount,iGet;
   var iCDId,iRandomId,iShow,iChangeId;
   window.onload = function(){
    //Create table createTable();
    //Assign values ​​to the tag element variables init();
    //Register event for the button oButStart.onclick=startGame;
    oButEnd.onclick=endGame;
   }
   //Start the game function startGame(){
    iAll=parseInt(oTextTime.value)*60;
    iCD=iAll;
    //Execute countdown every 1 second iCDId=window.setInterval(setCD,1000);
    iShow = parseInt (oTextShow.value);
    iHide=parseInt(oTextHide.value);
    iCount=0;
    iGet=0;
    //Randomly display a td every iShow+Hide
    randomId();
    iRandomId=window.setInterval(randomId,(iShow+iHide)*1000);
    oButStart.disabled="disabled";
    oButEnd.disabled="";
   }
   //Random td
   function randomId(){
    iCount++;
    var index = parseInt (Math.random() * collTd.length);
    oTdMouse=collTd[index];
    //Change the background image oTdMouse.style.backgroundImage="url('images/01.jpg')";
    //Wait for the show time to end and then set the background image back iShowId=window.setTimeout("oTdMouse.style.backgroundImage='url(images/00.jpg)';",iShow*1000);
   }
   //Set countdown function setCD(){
    iCD--;
    oTextCD.value=iCD;
    //Record the score every second var message="Total "+iCount+" pieces, hit "+iGet+" pieces!";
    oSpanScore.innerHTML=message.fontcolor("blue").bold();
    if(iCD<=0){
     endGame();
    }
   }
   //End the game function endGame(){
    oButEnd.disabled="disabled";
    oButStart.disabled="";
    window.clearInterval(iCDId);
    window.clearInterval(iRandomId);
   }
   //Assign values ​​to label element variables function init(){
    oButStart=document.getElementById("but_start");
    oButEnd=document.getElementById("but_end");
    
    oTextTime=document.getElementsByName("text_time")[0];
    oTextCD=document.getElementsByName("text_CD")[0];
    oTextHide=document.getElementsByName("text_hide")[0];
    oTextShow = document.getElementsByName("text_show")[0];
    
    oSpanScore = document.getElementById("span_score");
    oTextCD.value=60;
    oButEnd.disabled="disabled";
   }
   //Dynamically generate table function createTable(){
    var oDivRight = document.getElementById("div_right");
    var oTab=document.createElement("table");
    oTab.id="tab";
    for(var i=0;i<6;i++){
     var oTr=document.createElement("tr");
     for(var j=0;j<5;j++){
      var oTd = document.createElement("td");
      oTr.appendChild(oTd);
      collTd.push(oTd);
      //Add click events to all td oTd.onclick=function(){
       if(this==oTdMouse){
        //Judge whether the background image of the current cell is 01.jpg
        if(this.style.backgroundImage.indexOf("01.jpg")!=-1){
         //Get one point iGet++;
         //Change the background image to 02.jpg
         oTdMouse.style.backgroundImage="url('images/02.jpg')";
         //Wait 0.2 seconds to change to 00.jpg
         iChangeId=window.setTimeout("oTdMouse.style.backgroundImage='url(images/00.jpg)';",200);
         var message="Total "+iCount+" pieces, hit "+iGet+" pieces!";
         oSpanScore.innerHTML=message.fontcolor("blue").bold();
        }
        
       }
      }
     }
     oTab.appendChild(oTr);
    }
    oDivRight.appendChild(oTab);
   }
</script>