function gettaill() {
if (document.body)
{
var larg = (document.body.clientWidth);
var haut = (document.body.clientHeight);
} 
else
{
var larg = (window.innerWidth);
var haut = (window.innerHeight);
}

var coeff = 50/100;
larg = coeff*larg;
haut = coeff*haut;

}

function getlarg() {
if (document.body)
{
var larg = (document.body.clientWidth);
} 
else
{
var larg = (window.innerWidth);
}

var coeff = 50/100;
larg = coeff*larg;
return larg;

}

function gettaill() {
if (document.body)
{
var haut = (document.body.clientHeight);
} 
else
{
var haut = (window.innerHeight);
}

var coeff = 50/100;
haut = coeff*haut;
return haut;
}

function bouge(yn,xn) {
document.getElementById('bak').style.top = yn+"px";
document.getElementById('bak').style.left = xn+"px";
}
var yd = 0;
var xd = 0;
var direction = "basdroite";


function coord() {


if (document.body)
{
var larg = (document.body.clientWidth);
var haut = (document.body.clientHeight);
} 
else
{
var larg = (window.innerWidth);
var haut = (window.innerHeight);
}

var coeff = 50/100;
larg = coeff*larg;
haut = coeff*haut;




if (direction == "basdroite") {
if (yd > -haut) { yd = yd-1; }
if (xd > -larg) { xd = xd-1; }
if (xd <= -larg && yd <= -haut) { direction = "hautdroite"; }
}
if (direction == "hautdroite") {
if (yd <= 0) { yd = yd+1; }
if (yd >= 0 && xd <= -larg) { direction = "basgauche";}
}
if (direction == "basgauche") {
if (yd > -haut) { yd = yd-1; }
if (xd <= 0) { xd = xd+1; }
if (xd >= 0 && yd <= -haut) { direction = "hautgauche"; }
}
if (direction == "hautgauche") {
if (yd <= 0) { yd = yd+1; }
if (xd >= 0 && yd >= 0) { direction = "basdroite"; }
}
//Script by webmaster@sethclan.com 
//document.getElementById('direct').value = direction;

bouge(yd,xd);
setTimeout("coord()",100);
}