// Javascript for running presentations, originally based on code from 
// developer.netscape.com/docs/technote/javascript/prestemp/prestemp.html

last_slide = slides.length/2 - 1;
if (last_slide < 0) last_slide = 0;
slidetitle = "";
current_slide = 0;

// Go to slide number slide_num.
function goto_slide(slide_num)
{
	if(slide_num < 0 || slide_num > last_slide)
	    alert("Please enter number between 0 and " + last_slide);
	else 
	{	current_slide = Math.abs(slide_num);

		// update title
		slidetitle = slides[2*current_slide+1];
		frames.header.location.reload();

		// update slide
		frames.slide.location = slides[2*current_slide];

                // update displayed page count in goto field
                frames.next.document.forms.gotoform.slidenum.value = 
			current_slide;
	}
}

// Display previous slide in sequence.
function prev_slide()
{	if (current_slide == 0)
	    alert("You are already at the first slide.");
        else goto_slide(current_slide - 1);
}


// Display next slide in sequence.
function next_slide()
{	if (current_slide == last_slide)
	    alert("You are already at the last slide.");
        else goto_slide(current_slide + 1);
}