function getParam(PARAM, DEF){
	var str = top.location.search;
	var reg = new RegExp(PARAM+"=([^&]+)");
	var result = str.match(reg);
	if(result != null){
		return result[1];
	}	
	return DEF;	
}
function changeImage(ID, SRC){
	document.getElementById(ID).src = SRC;
}
function display(ID){
	document.getElementById(ID).style.display = 'block';
}
function hide(ID){
	document.getElementById(ID).style.display = 'none';
}
function displayHide(ID){
	if(document.getElementById(ID).style.display == 'none'){
		document.getElementById(ID).style.display = 'block';
	}else{
		document.getElementById(ID).style.display = 'none';
	}
}