Graphing

Ok, so im really new at this True Basic stuff, and have lots of assignments to complete with it for my Algebra Trig class...
but theres this one really simple assignment that i just cant seem to finnish correctly. Ok, so heres the list:

PRINT tab (25);"Graphing"
PRINT
PRINT"The objective of this program was to make a graph given two points on a line."
PRINT
DO until a$ = "no"
INPUT prompt"What are the coordinates of the two points?":x1,y1,x2,y2
IF x1 = x2 then
PRINT"This is a vertical line, it cannot be graphed"
END IF
IF y1 = y2 then
PRINT"This is a horizontal line, it cannot be graphed"
END IF
IF x1<>x2 then
GRAPH
END IF
IF y1<>y2 then
GRAPH
END IF
LOOP
END

What i just cant seem to get is how to graph the points in the last about 9 lines.
and ALSO, i cant figure out what exactly im supposed to say to end the loop.
help please?

Comments

Graphing

To draw a line between two points, use

PLOT LINES: x1,y1; x2,y2

This will plot horizontal and vertical lines with no problem so you don't need the tests in there unless that's part of your assignment.

Add these lines before the word LOOP

input prompt "Any more to do (yes/no)? ": a$
let a$=lcase$(a$)

Thanks!!

thank you soooooo much, i will try that!