function showHideAnswer()
{
    var id = this.id;

   	var lastIndexOf_ = id.lastIndexOf("_");
   	
   	var controlPrefix = id.substring(0, lastIndexOf_ + 1);
   	
   	var controlId = id.substring(lastIndexOf_ + 1, id.length );
   	
	var numericID = controlId.replace(/[^\d]/g,'');

	var obj = document.getElementById(controlPrefix + 'a' + numericID);
	var sign = document.getElementById(controlPrefix + 'sign'+ numericID);
	if(obj.style.display=='block'){
		obj.style.display='none';
		sign.innerHTML = '+';
	}else{
		obj.style.display='block';
		sign.innerHTML = '-';
	}		
}
	
function initShowHideContent()
{
	var divs = document.getElementsByTagName('DIV');
	for(var no=0;no<divs.length;no++){
		if(divs[no].className=='question'){
			divs[no].onclick = showHideAnswer;
		}			
	}	
}