var slideint = 0;
var slideHeight = 250;
var sliding = false;
var slideSpeed = 10;

function Slide()
{
   if(sliding)
      return;
   sliding = true;
   if(slideHeight == 250)
      slideint = setInterval('SlideUpRun()', 20);
   else
      slideint = setInterval('SlideDownRun()', 20);
}

function SlideUpRun()
{
   slide = document.getElementById('slidediv');
   if(slideHeight <= 20)
   {
      sliding = false;
      slideHeight = 20;
      slide.style.height = '20px';
      clearInterval(slideint);
   }
   else
   {
      slideHeight -= slideSpeed;
      if(slideHeight <20)
         slideHeight = 20;
      slide.style.height = slideHeight + 'px';
   }
}

function SlideDownRun()
{
   slide = document.getElementById('slidediv');
   if(slideHeight>= 250)
   {
      sliding = false;
      slideHeight = 250;
      slide.style.height = '250px';
      clearInterval(slideint);
   }
   else
   {
      slideHeight += slideSpeed;
      if(slideHeight> 250)
         slideHeight = 250;
      slide.style.height = slideHeight + 'px';
   }
}