Live Demo: JavaScript Program to Display all Prime Number

<html>
<body>
   <script>
     function primeall()
     {
	    var j,b;
    	var lb=parseInt(prompt("enter the lower bound"));
	    var n=parseInt(prompt("enter the upper bound"));
	    for(i=lb;i<=n;i++)
	    {
            b=0;
            for(j=1;j<=i;j++)
            {
             if(i%j==0)
             {
               b=b+1;
             }
            }
            if(b==2)
            {
              document.write(i+"</br>");
		    }
        }
     }
    </script>
    <form>
         <input type="button" value="prime number" onclick="primeall();">
    </form>
</body>
</html>