i thought about this after i posted it here is the code in use but in darkbasic format

sync on
synce rate 0

an=10
tx#=320
ty#=240
x#=320
y#=240

do
cls


text 1,1,"true angle "+str$(an)

text 1,20,"Difference between x''s "+str$(newx#)
text 1,40,"Difference between y''s "+str$(newy#)
text 1,60,"My angle "+str$(angle#)


x1#=0+cos(an)*50
y1#=240+sin(an)*50

dx#=x#-mousex()
dy#=y#-mousey()

angle#=int(ca(dx#,dy#))


line x#,y#,mousex(),mousey()

if leftkey()=1 then an=wrapvalue(an-1)
if rightkey()=1 then an=wrapvalue(an+1)


sync
loop

function ca(dx#,dy#)
quadflag=0
if dx#<0 then dx#=dx#*-1 : inc quadflag
if dy# < 0 then dy#=dy#*-1 : quadflag= quadflag+2
if dx# <> 0
angle#=ATAN(dy#/dx#)
else
angle#=ATAN(dy#)
endif

if quadflag=1 then angle# = 180-angle#
if quadflag=2 then angle# = 360-angle#
if quadflag=3 then angle# = 180+angle#

if angle# > 0 then angle# =angle# +.50

angle#=wrapvalue(angle#+180)

endfunction angle#

i forgot to mention darkbasic uses degrees not rads sorry for the confusion.

Thanks a lot guys with your help, and some little thinking i was able to figure it out ... you guys rock ...

dfawcett Thanks a lot man for the professional explaination ... WOW! i never thought anyone can be this much helpful and supportive ...

Thanks a million rodzilla and daher ... i appricate everything you wrote

again you guys rock

here is how it finally worked for me ...

float dx = wx_pos - player.wx_pos;
float dy = wy_pos - player.wy_pos;

int quadflag=0;

if (dx < 0)
{
dx = dx * -1;
quadflag ++;
}

if (dy < 0)
{
dy = dy * -1;
quadflag += 2;
}

if (quadflag == 0)
{
cTanksceneroty = RAD2DEG * atan2(dx,dy);
cTanksceneroty = 180 + cTanksceneroty;
}

if (quadflag == 1)
{
cTanksceneroty = RAD2DEG * atan2(dy,dx);
cTanksceneroty = 90 + cTanksceneroty;
}

if (quadflag == 2)
{
cTanksceneroty = RAD2DEG * atan2(dy,dx);
cTanksceneroty = 270 + cTanksceneroty;
}

if (quadflag == 3)
{
cTanksceneroty = RAD2DEG * atan2(dx,dy);
cTanksceneroty = cTanksceneroty;
}

glRotatef(cTanksceneroty,0,1.0f,0);

sorry for the delay i was busy but i think u got what u want,
thanx 2 ol...



"The Railgun Master"
DaHeR