function changeImage1_1_2(){
document.contents1_1.src="images/enter1_2.gif";
}

function changeImage1_1_1(){
document.contents1_1.src="images/enter1_1.gif";
}


function changeImage1_2_2(){
document.contents1_2.src="images/enter2_2.gif";
}

function changeImage1_2_1(){
document.contents1_2.src="images/enter2_1.gif";
}

function changeImage2_2(){
document.contents2.src="images/enter_chat2.gif";
}

function changeImage2(){
document.contents2.src="images/enter_chat.gif";
}

function changeImage3_2(){
document.event.src="images/event_2.gif";
}

function changeImage3(){
document.event.src="images/event_1.gif";
}

function changeImage4_2(){
document.beginner.src="images/beginner_2.gif";
}

function changeImage4(){
document.beginner.src="images/beginner_1.gif";
}