function switchTab( id )
{

    if ( id == "tab1" ) {

     document.getElementById( 'tab1' ).className = "active";
     document.getElementById( 'tab2' ).className = "";
     document.getElementById( 'tab3' ).className = "";

     } 
	 	 else if(id == "tab3"){
	 document.getElementById( 'tab3' ).className = "active";
document.getElementById( 'tab2' ).className = "";
     document.getElementById( 'tab1' ).className = "";


     }

	 else if(id == "tab2") {
document.getElementById( 'tab2' ).className = "active";
     document.getElementById( 'tab1' ).className = "";
	      document.getElementById( 'tab3' ).className = "";


     }

}