function show_description(total){
 if(document.getElementById('show_des_heading')&&document.getElementById('hide_des_heading')){
	document.getElementById('show_des_heading').className ='hide_descriptiion'; 
	document.getElementById('hide_des_heading').className = 'show_descriptiion';
	for(var i=1;i<=total;i++)
	document.getElementById('show_des'+i).className = 'show_descriptiion';
	}
}

function hide_description(total){
 if(document.getElementById('show_des_heading')&&document.getElementById('hide_des_heading')){
	document.getElementById('show_des_heading').className ='show_descriptiion'; 
	document.getElementById('hide_des_heading').className = 'hide_descriptiion';
	for(var i=1;i<=total;i++)
	document.getElementById('show_des'+i).className = 'hide_descriptiion';
	}
}