function preload() {

   img0=new Image(0,0);
   img0.src='../images/source_co.gif';
   img1=new Image(0,0);
   img1.src='../images/minerale_co.gif';
   img2=new Image(0,0);
   img2.src='../images/mineraux_co.gif';
   img3=new Image(0,0);
   img3.src='../images/source_co_r.gif';
   img4=new Image(0,0);
   img4.src='../images/minerale_co_r.gif';
   img5=new Image(0,0);
   img5.src='../images/mineraux_co_r.gif';
   img6=new Image(0,0);
   img6.src='../images/contact_co.gif';
   img7=new Image(0,0);
   img7.src='../images/contact_co_r.gif';

   img10=new Image(0,0);
   img10.src='../images/degazage_co.gif';
   img11=new Image(0,0);
   img11.src='../images/oxydation_co.gif';
   img12=new Image(0,0);
   img12.src='../images/filtration_co.gif';
   img13=new Image(0,0);
   img13.src='../images/regazage_co.gif';
   img14=new Image(0,0);
   img14.src='../images/degazage_co_r.gif';
   img15=new Image(0,0);
   img15.src='../images/oxydation_co_r.gif';
   img16=new Image(0,0);
   img16.src='../images/filtration_co_r.gif';
   img17=new Image(0,0);
   img17.src='../images/regazage_co_r.gif';
   img18=new Image(0,0);
   img18.src='../images/degazage_co_t.jpg';
   img19=new Image(0,0);
   img19.src='../images/oxydation_co_t.jpg';
   img20=new Image(0,0);
   img20.src='../images/filtration_co_t.jpg';
   img21=new Image(0,0);
   img21.src='../images/regazage_co_t.jpg';
   img22=new Image(0,0);
   img22.src='../images/vide.jpg';

	document.description.src = '../images/vide.jpg';
}

function rollDegazage() {
	document.description.src = '../images/degazage_co_t.jpg';
	document.degazage.src = '../images/degazage_co_r.gif';
}

function unrollDegazage() {
	document.description.src = '../images/vide.jpg';
	document.degazage.src = '../images/degazage_co.gif';
}

function rollOxydation() {
	document.description.src = '../images/oxydation_co_t.jpg';
	document.oxydation.src = '../images/oxydation_co_r.gif';
}

function unrollOxydation() {
	document.description.src = '../images/vide.jpg';
	document.oxydation.src = '../images/oxydation_co.gif';
}

function rollFiltration() {
	document.description.src = '../images/filtration_co_t.jpg';
	document.filtration.src = '../images/filtration_co_r.gif';
}

function unrollFiltration() {
	document.description.src = '../images/vide.jpg';
	document.filtration.src = '../images/filtration_co.gif';
}

function rollRegazage() {
	document.description.src = '../images/regazage_co_t.jpg';
	document.regazage.src = '../images/regazage_co_r.gif';
}

function unrollRegazage() {
	document.description.src = '../images/vide.jpg';
	document.regazage.src = '../images/regazage_co.gif';
}