function changeTab(tabNum){

		//	alert("tabNum:"+tabNum);
		tabNum=tabNum.toString();
		tab = document.getElementById('contentTab');
		
		//document.getElementById('tabWeb1').style.visibility="hidden";
		
		//document.getElementById('contentTab').style.visibility="hidden";
		
		document.getElementById('tab1').style.visibility="hidden";
		document.getElementById('botton_Tab1').className ="botton_Tab";
		
		document.getElementById('tab2').style.visibility="hidden";
		document.getElementById('botton_Tab2').className ="botton_Tab";
		
		document.getElementById('tab3').style.visibility="hidden";
		document.getElementById('botton_Tab3').className ="botton_Tab";
		
		document.getElementById('tab4').style.visibility="hidden";
		document.getElementById('botton_Tab4').className ="botton_Tab";
		
		document.getElementById('tab'+tabNum).style.visibility="visible";
		document.getElementById('botton_Tab'+tabNum).className ="botton_Tab_Over";
		//tab.innerHTML = 

}
//