How do I make a quadratic function program on my ti 84 calculator?

I want a program that will run just like this:

Having a trinomial such as ax^2+bx+c

Program asks for "a".

User inputs "a".

Program asks for "b".

User inputs "b".

Program asks for "c".

User inputs "c".

Program calculates the roots using the quadratic equation:

variable1 = (-b + sqrt(b^2-4ac))/(2a)

varible2 = (-b - sqrt(b^2-4ac))/(2a)

Program displays variable1 and variable2.

This is what i have so far:

PROGRAM:QUAD

:ClrHome

:Input "A VALUE?",A

:Input "B VALUE?",B

:Input "C VALUE?",C

:Q=((-1*B)+(sqrt((B*B)-(4*A*C))))/(2A)

:O=((-1*B)-(sqrt((B*B)-(4*A*C))))/(2A)

:Disp "ROOTS ARE "

:Disp Q

:Disp " AND "

:Disp O

:Pause

The program isn't working because my calculator has Q and O stored as zero so whenever i run it, i always get the output to say:

ROOTS ARE

0

AND

0

How do i create a "fresh" variable for my program? (meaning one that isn't already defined)

Otherwise, the program works flawlessly. I get no errors unless I put in number that give an imaginary number.

If you're trying to figure this one out, here's a trinomial that does have real roots:

x^2 - 2x - 3

Roots should be, -1 and +3.

Thank you so much for helping me out.

And on a side note, I need this for my chem class because we have trinomials that are like this:

5.56*10^(-11) - 5.56*10^(-10)x - x^2

and i can't just graph it and find the y-intercept because the value of x is so small it doesn't detect a change in sign.