I'm creating a simple Isometric game using HTML5 and Javascript, but I can't seem to get the display to work, at the moment i have 9 tiles that have X and Y positions and the player has a X and Y position, the players X and Y properties are set to 100, and the tiles are as shown

tiles[0] = new Array(3);
tiles[1] = new Array(3);
tiles[2] = new Array(3);
tiles[0][0] = new point2D( 100, 100);
tiles[0][1] = new point2D( 160, 100);
tiles[0][2] = new point2D( 220, 100);
tiles[1][0] = new point2D( 100, 160);
tiles[1][1] = new point2D( 160, 160);
tiles[1][2] = new point2D( 220, 160);
tiles[2][0] = new point2D( 100, 220);
tiles[2][1] = new point2D( 160, 220);
tiles[2][2] = new point2D( 220, 220);

Now I use this method to work out the isometric position

function twoDToIso( point )
{
var cords = point2D;
cords.x = point.x - point.y;
cords.y = (point.x + point.y) / 2;
return cords;
}

point2D is

function point2D( x, y)
{
this.x = x;
this.y = y;
}

Now this i'm sure does work out the correct positioning, but here is the output

I just need to move my player position a tiny bit, but is that the best way to display my player position in the right position?

Canvas