// Creating a 10x2 two dimensional array
	var positionMatrix = new Array(10);
	for (var i = 0; i < positionMatrix.length; i++) {
	    positionMatrix[i] = new Array(2);
	}

	var x = "163px"
	var oy = 159;
 	var dy = 46;

	// calque vie pratique
	positionMatrix[0][0] = x;
	positionMatrix[0][1] = oy + 0*dy + "px";
	// calque temps libre
	positionMatrix[1][0] = x;
	positionMatrix[1][1] = oy + 1*dy + "px";
	// calque jeunesse
	positionMatrix[2][0] = x;
	positionMatrix[2][1] = oy + 2*dy + "px";
	// calque environnement
	positionMatrix[3][0] = x;
	positionMatrix[3][1] = oy + 3*dy + "px";
	// calque decouvrir la ville
	positionMatrix[4][0] = x;
	positionMatrix[4][1] = oy + 4*dy + "px";
	// calque vie publique
	positionMatrix[5][0] = x;
	positionMatrix[5][1] = oy + 5*dy + "px";
	// calque 
	positionMatrix[6][0] = x;
	positionMatrix[6][1] = oy + 6*dy + "px";
	// calque 
	positionMatrix[7][0] = x;
	positionMatrix[7][1] = oy + 7*dy + "px";
	// calque 
	positionMatrix[8][0] = x;
	positionMatrix[8][1] = oy + 8*dy + "px";
	// calque 
	positionMatrix[9][0] = x;
	positionMatrix[9][1] = "oy + 9*dy + px";