function jump(){
	var agent = navigator.userAgent.toLowerCase() ;
	var Win_OS = agent.indexOf("win") != -1 ;
	var Mac_OS = agent.indexOf("mac") != -1 ;
	var Linux_OS = agent.indexOf("lin") != -1 ;
	var Other_OS = agent.indexOf("win") == -1 &&
		agent.indexOf("mac") == -1 &&
		agent.indexOf("lin") == -1 ;
	if(Win_OS || Mac_OS || Linux_OS){
		location.href = "index.html";
	}
}