<script type="text/javascript">

  function up(){ alert("up");}

function down(){alert("down");}

  function left(){ alert("left");}

function right(){alert("right");}


  function jumpPage(){

    if(event.keyCode==37){

      left(); return ;

    }

    if(event.keyCode==38){

       up();return ;

    }

     if(event.keyCode==39){

      right();return ;

    }

    if(event.keyCode==40){

      down();return ;

    }

    document.onkeydown=jumpPage;


  }


</script>