function tab(tabId)
{
    var currTabElem = tabId;
    var currTabElem1 = document.getElementById(tabId);
     if(currTabElem == "Tab1")
     {
        document.getElementById("Tab1").className="Tab1SeeWhoAct";
        document.getElementById("Tab3").className="Tab3CochngProInAct";
        document.getElementById("Tab2").className="Tab2TryBeforeInAct";
        document.getElementById("TabDiv2").style.display='none';
        document.getElementById("TabDiv3").style.display='none';
        document.getElementById("TabDiv1").style.display='block';
     }
     else if(currTabElem == "Tab2")
     {
        document.getElementById("Tab2").className="Tab2TryBeforeAct";
        document.getElementById("Tab1").className="Tab1SeeWhoInAct";
        document.getElementById("Tab3").className="Tab3CochngProInAct";
        document.getElementById("TabDiv1").style.display='none';
        document.getElementById("TabDiv3").style.display='none';
        document.getElementById("TabDiv2").style.display='block';
     }
     else if(currTabElem == "Tab3")
     {
        document.getElementById("Tab3").className="Tab3CochngProAct";
        document.getElementById("Tab2").className="Tab2TryBeforeInAct";
        document.getElementById("Tab1").className="Tab1SeeWhoInAct";
        document.getElementById("TabDiv1").style.display='none';
        document.getElementById("TabDiv2").style.display='none';
        document.getElementById("TabDiv3").style.display='block';
     }
}