function tabActive(tab_pre,tabid) { 
var tTab = document.getElementById(tab_pre+"tab").getElementsByTagName("div"); 
var sTab = document.getElementById(tab_pre+tabid);
var content_tabid =tab_pre+ "content_"+tabid;

for (var i=0; i<tTab.length; i++) { 
tTab[i].className=tTab[i].className.replace(new RegExp("( ?|^)"+tab_pre+"tab_hover\\b"), "");  
tTab[i].className=tTab[i].className.replace(new RegExp("( ?|^)"+tab_pre+"tab_nothover\\b"), "");
tTab[i].className+=(sTab.className.length>0? " ": "") + tab_pre+"tab_nothover"; 
}

sTab.className=sTab.className.replace(new RegExp("( ?|^)"+tab_pre+"tab_nothover\\b"), "");  
sTab.className+=(sTab.className.length>0? " ": "") + tab_pre+"tab_hover";

document.getElementById(tab_pre+"tab_content").innerHTML=document.getElementById(content_tabid).innerHTML;
}