ns4 = (document.layers)? true:false
ie4 = (document.all)? true:false
 
contact0 = new Image();
contact1 = new Image();
reseau0 = new Image();
reseau1 = new Image();
services0 = new Image();
services1 = new Image();
presentation0 = new Image();
presentation1 = new Image();


// chargement des images dans le cache

contact0.src ="images/contact0.gif" 
contact1.src ="images/contact1.gif" 
reseau0.src ="images/reseau0.gif" 
reseau1.src ="images/reseau1.gif" 
services0.src ="images/services0.gif" 
services1.src ="images/services1.gif" 
presentation0.src ="images/presentation0.gif" 
presentation1.src ="images/presentation1.gif" 


// survol des images
function show(sens) {
switch(sens) {
		case "entree1" :
   document.e1.src = contact0.src   
   break;
   case "sortie1" :
 document.e1.src = contact1.src
       break;
       	case "entree2" :
   document.e2.src = reseau0.src  
   break;
   case "sortie2" :
 document.e2.src = reseau1.src
       break;
	case "entree3" :
   document.e3.src = services0.src  
   break;
   case "sortie3" :
 document.e3.src = services1.src
       break;
       case "entree4" :
   document.e4.src = presentation0.src  
   break;
   case "sortie4" :
 document.e4.src = presentation1.src
       break;
       }
}