TI 84+ calculator program help

[Ninjakiwi]

I'm using a TI-84 PLUS and have been making programs lately for common math re occurrences. One of them was to calculate the slope of a line between two points, and it is plugged in to read:
:ClrHome
: Disp "SLOPE"
:Input "Y1:",A
:Input "Y2:",B
:Input "X1:",C
:Input "X2:",D
:ClrHome
: Disp "SLOPE:"
: Disp (B-A)/(D-C)
:End

I tested it out with points (1,-4) and (-4,2), which the answer should be -1.2 -- With Y1: -4, Y2: 2, X1: 1, X2: -4, I get "ERR:SYNTAX". If I choose to quit then it exits the program and says "SLOPE: -1.2 Error". If I choose to goto, it takes me to Pgrm Edit and puts me down at :End.

Does anyone who is familiar with the TI84 calculator and programming know what my problem is? The distance formula I made does the same thing, but a more complex program I made to calculate either compound, continuous, or present interest doesn't run into this.

Thanks!

[llDemonll]

:ClrHome
:Prompt Y1, Y2, X1, X2
:Y1-Y2→A
:X2-X1→B
:B/A→C
:DISP C

I can't tell you the problem, but that is one way to simplify the program (granted, I haven't touched a calculator to program in a few years, and that was on a TI-83+

[Arcilux]

Been a long while since using TI Basic, but I think you need a STOP as well as END