function showBox(id)  
{ 
 var doit = false;
 var i=0;
 var boxArray = new Array(4);
 var tabArray = new Array(4);
 tabArray[0]="tab_desc";
 boxArray[0]="desc"; 
 tabArray[1]="tab_features";
 boxArray[1]="features"; 
 tabArray[2]="tab_specs";
 boxArray[2]="specs"; 
 tabArray[3]="tab_reviews";
 boxArray[3]="reviews"; 
 

for (i=0; i<4; i++)
{
  if (i == id) {
    document.getElementById(tabArray[i]).className='boxTabOn';	
 	document.getElementById(boxArray[i]).style.display='';	
  }
  else {
    document.getElementById(tabArray[i]).className='boxTabOff';	
 	document.getElementById(boxArray[i]).style.display='none';	
  }
}
}