Coordonnées souris sur map iso

[Aleskweb]

Resultas :

function coord(pEvt:Event):void{

xsouris = mouseX-600;
ysouris = mouseY-200;
xsouris = xsouris/(2*40) + ysouris/(2*20);
ysouris = -xsouris/(2*40) + ysouris/(2*20);
affcoord.text = " Souris X = " + mouseX + " ("+xsouris+")"+ " Souris Y = " + mouseY +" ("+ysouris+")";

}

Les x marchent, mais pas les y....