change_style(Window, XOR, AND, OR)
Changes the stile of the Window. The new stile is the old one modified by XOR, AND and OR.
XOR gives bits which have to be reversed. For example if XOR is 5 then bits 1 and 4 will be reversed.
AND gives which bits have to be zero. For example if AND is 5 then bits 1 and 4 will be set to zero.
OR gives which bits have to be one. For example if OR is 5 then bits 1 and 4 will be set to one.
Actually the result is:
New_value is ((Old_value xor XOR) /\ \AND) \/ OR