syntax:

gd.colorTransparent(color)

where:

color - color index to make transparent.

return:

void.

description:

This method sets the specified color index to be the transparent index. To indicate that there is to be no transparent color, the value -1 should be passed as the color index.

see:

#link <gd>

example:

var gd = new GD(64,64);

var index = gd.colorAllocate(0,0,0);

gd.colorTransparent(index);

// The background (and all black pixels)

// is transparent