/* Javascript code to manage the page sliding */
pos_upto = 0;
page_divid = null;
page_upto = 1; //start

/* This is the width of your menu division (menu_div) */
menu_width = 150;


function slide_to(div_code) {

	pos_to = document.getElementById(div_code).style.left;
	page_divid = document.getElementById('page_div');

	//gives up the page number, remember each div is named page1, page2 etc...
	page_upto = div_code.slice(4);
	
	/* format the pos_to to remove the px or em at the end. */
	pos_to = pos_to.slice(0,pos_to.length-2);
	distance = 0;
	
	if (pos_to > 0) pos_to -= menu_width;
	
	slideInt = setInterval('_slider(pos_to)',20);
}


function _slider(pos_to) {

	/* move pos_upto backwards to be in line with pos_to */
	if (pos_upto > pos_to) {
		distance = (pos_upto - pos_to) * 0.05;
		pos_upto -= distance;
	}
	else {
		distance = (pos_to - pos_upto) * 0.05;
		pos_upto += distance;
	}
	
	if (Math.round(pos_upto) == pos_to) {
		clearInterval(slideInt);
	}
	
	page_divid.style.left = '-' + pos_upto + 'px';
}

/* Moves to the next slide */
function do_next() {
	if (document.getElementById('page'+(parseInt(page_upto) + 1))) {
		slide_to('page'+(parseInt(page_upto) + 1));
	}
}

/* Moves to a previus slide */
function do_previous() {
	if (document.getElementById('page'+(parseInt(page_upto) - 1))) {
		slide_to('page'+(parseInt(page_upto) - 1));
	}
}