{Clear the screen and display a title at the top}
display_title(++ TRANSFORMATION of CELESTIAL COORDINATES ++)

{Set the delimiter to % so that commas can be used in the prompt string}
set_delimiter(%)

{Get the coordinates to transform from and into}
ask_for_character(Transform from which system [h,a,r,e,g]%hareg%c1)
ask_for_character(........... to which system [h,a,r,e,g]%hareg%c2)
new_line

{Write an appropriate message depending on the coordinates}
if (c1=h)
    write_string(Please input hour angle and declination:)
end_if
if (c1=g)
    write_string(Please input galactic longitude and latitude:)
end_if
if (c1=r)
    write_string(Please input right ascension and declination:)
end_if
if (c1=a)
    write_string(Please input azimuth and altitude:)
end_if
if (c1=e)
    write_string(Please input ecliptic longitude and latitude:)
end_if
new_line

{Get the coordinates themselves which are to be transformed...}
ask_for_coordinates(c1)

{... and transform them}
convert_coordinates(c1%c2)

{Set the text colour to red...}
set_normal_text(4)

{... and display the result}
new_line
display_coordinates(c2)

{Reset the text colour to its normal state}
set_normal_text(7)
new_line

{Ask if we want to do it again}
ask_for_repeat