[Dim@]

Можно было сделать проще (это я про свой код), но я просто торопился

function ShowOrHide(id) {
if((document.getElementById('newsbar').style.display=='none'&&document.getElementById(id).style.display=='none')||(document.getElementById(id).style.display=='block'&&document.getElementById('newsbar').style.display=='block')){
document.getElementById(id).style.display='block'
document.getElementById('newsbar2').style.display='none'
document.getElementById('newsbar3').style.display='none'
}
if((document.getElementById('newsbar2').style.display=='none'&&document.getElementById(id).style.display=='none')||(document.getElementById(id).style.display=='block'&&document.getElementById('newsbar2').style.display=='block')){
document.getElementById('newsbar').style.display='none'
document.getElementById(id).style.display='block'
document.getElementById('newsbar3').style.display='none'
}
if((document.getElementById('newsbar3').style.display=='none'&&document.getElementById(id).style.display=='none')||(document.getElementById(id).style.display=='block'&&document.getElementById('newsbar3').style.display=='block')){
document.getElementById('newsbar').style.display='none'
document.getElementById(id).style.display='block'
document.getElementById('newsbar2').style.display='none'
}
	 }