<script type="text/javascript">// <![CDATA[
var x=prompt("I am thinking of a number,Enter a number between 0 and 10:","");
try
  { 
  if(x>2)
    {
    throw "Err1";
    }
  else if(x<2)
    {
    throw "Err2";
    }
  else if(isNaN(x))
    {
    throw "Err3";
    }
  }
catch(er)
  {
  if(er=="Err1")
    {
    alert("Error! this isn't the number! Try again!!");
    }
  if(er=="Err2")
    {
    alert("Error! this isn't the number! try harder!");
    }
  if(er=="Err3")
    {
    alert("Error! The value is not a number, please enter a number next time");
    }
  }
// ]]></script>