document.oncontextmenu = function (event){
	if(window.event){
		event = window.event;
	}try{
		var the = event.srcElement;
		if (!((the.tagName == "INPUT" && the.type.toLowerCase() == "text") || the.tagName == "TEXTAREA")){
			return false;
		}
		return true;
	}catch (e){
		return false; 
	} 
}

屏蔽右键菜单