function show(what) { 
document.getElementById("text").style.display='none'; 
document.getElementById("text1").style.display='none'; 
document.getElementById(what).style.display='block'; 
} 


function show2(what2) { 
document.getElementById("link").style.display='none'; 
document.getElementById("link1").style.display='none'; 
document.getElementById(what2).style.display='block'; 
} 

function show3(what3) { 
document.getElementById("text2").style.display='none'; 
document.getElementById("text3").style.display='none'; 
document.getElementById(what3).style.display='block'; 
} 

function show4(what4) { 
document.getElementById("link2").style.display='none'; 
document.getElementById("link3").style.display='none'; 
document.getElementById(what4).style.display='block'; 
}