Use JS to control the keyboard up and down key

  This article mainly introduces the use of JS to control the keyboard up and down key sample code. Need friends can come to the reference, I hope to help you.

This is a JS primary code, want to learn JS friend, you can study under or expand, it is best to use JS to achieve the entire keyboard control, that feeling is very interesting.   Specific code as follows:   code as follows: <style> tr.highlight{background: #08246B; color:white} </style> <table Border= "1" width= "70%" id= "ice" > <tr> <td><input type= ' text ' ></td> <td><input Type= ' text ' ></td> <td><input type= ' text ' ></td> <td><input type= ' text ' ></ td> </tr> <tr> <td><input type= ' text ' ></td> <td><input type= ' text ' >< /td> <td><input type= ' text ' ></td> <td><input type= ' text ' ></td> </tr> <tr> <td><input type= ' text ' ></td> <td><input type= ' text ' ></td> <td> <input type= ' text ' ></td> <td><input type= ' text ' ></td> </tr> <tr> <td ><input type= ' text ' ></td> <td><input type= ' text ' ></td> <td><input type= ' Text ' ></td> <TD><input type= ' text ' ></td> </tr> <tr> <td><input type= ' text ' ></td> <TD ><input type= ' text ' ></td> <td><input type= ' text ' ></td> <td><input type= ' Text ' ></td> </tr> </table> <script language= "JavaScript" > <!--//define initialization row Var CurrentLine =-1; var currentcol=-1; Document.onkeydown=function (e) {  E=window.event| | E   Switch (e.keycode) {    case 37://Left       currentcol--;       Changeitem () ;       break;     Case 38://Up key       currentline--;       Changeitem ();       break;     CASE 39://Right button       currentcol++;       Changeitem ();       break;     CASE 40://Down key       currentline++;       Changeitem ();       break;     Default:      break;  }//arrow keys Invoke function Changeitem () {  if (document.all)     var it=document.getelementbyidx_x ("Ice"). CHILDREN[0];   Else     var it=document.getelementbyidx_x ("Ice");   for (i=0;i<it.rows.length;i++) {    it.rows[i].classname= "";  }   if (currentline<0) {& nbsp   Currentline=it.rows.length-1;  }   if (currentline==it.rows.length) {  currentline=0  }   var objtab=document.all.ice;   var objrow=objtab.rows[currentline].getelementsbytagname_r ("INPUT");   if (currentcol<0) {    currentcol=objrow.length-1  }else if (currentcol==objrow.length) {     currentcol=0;  }   Objrow[currentcol].select ();  //Commissioning use   it.rows[currentline].classname= "highlight"; }//--> </script>