function collapse(id){
	var project = document.getElementById('tb_'+id);
	var image1 = document.getElementById('img_1_'+id);
	var image2 = document.getElementById('img_2_'+id);
	$(project).slideToggle('slow');
	image1.style.display='none';	
	image2.style.display='';
}

function expand(id){
	var project = document.getElementById('tb_'+id);
	var image1 = document.getElementById('img_1_'+id);
	var image2 = document.getElementById('img_2_'+id);
	$(project).slideToggle('slow');
	image1.style.display='';	
	image2.style.display='none';
}