Anyone who knows Ada, pls. help me

I just began learning ada language and my professor asked us to make a program that will calculate the smallest distance between two points, and show what point they are. the range is from 20.0 .. -20.0 and delta x defines the x in the formula axx+bx+c. I made the program but I don't know which part in my logic is wrong, can anyone pls. help. and can I also pls ask if someone can teach me how to declare and use a function in a main program in ada. thank you very much.

this is my code :

with Ada.Text_IO, Ada.Float_Text_IO;
with ada.Numerics.Generic_elementary_functions;
use Ada.Text_IO, Ada.float_text_IO;
use Ada;

procedure Main is
Package squareRoot IS new ada.numerics.Generic_elementary_functions(float);
use SquareRoot;

Type ListArray is array (1..1000) of float;

x : ListArray;
y1 : ListArray;
y2 : ListArray;

a1 : Float;
a2 : Float;
b1 : float;
b2 : float;
c1 : float;
c2 : float;
dx : float;
DX1 : float;
DY1 : float;
DX2 : float;
DY2 : float;
OldX : Float;
point1 :float;
point2 :float;
Distance:float;
point1a : float;
point2a : float;
sumMulti : Float;
smallestdistance : float;

counter : Integer;
Limit:Integer;

begin

put ("Enter A for Function 1 : ");
get (a1);
New_Line;

put ("Enter A for Function 2 : ");
get (a2);
New_Line;

put ("Enter B for Function 1 : ");
get (B1);
New_Line;

put ("Enter B for Function 2 : ");
get (B2);
New_Line;

put ("Enter C for Function 1 : ");
get (C1);
New_Line;

put ("Enter C for Function 2 : ");
get (C2);
New_Line;

Put ("Enter delta x value :");
Get (dx);
New_Line;


counter := 1;
OldX := -20.0;

while (X(counter) <= 20.0) loop

x(Counter):=OldX;

y1(counter) := a1*OldX*OldX + b1*OldX + c1;
y2(counter) := a2*OldX*OldX + b2*OldX + c2;

counter := counter + 1;
OldX:= OldX + DX;

end loop;

limit:=Integer(40.00/dx);


for h in 1..Limit loop
dX1:=X(h);DY1:=Y1(h);

for i in 1..Limit loop

DX2:=X(i);DY2:=Y2(i);
SumMulti := (DX1-DX2)*(DX1-DX2)+(DY1-DY2)*(DY1-DY2);
Distance := SquareRoot.sqrt(sumMulti);

if DX1=-20.0 and DX2=-20.0 then
SmallestDistance:=Distance;
end if;

if Distance<=SmallestDistance then
SmallestDistance:=distance;

point1 := dX1;
Point1a := dY1;

Point2 := dX2;
Point2a := DY2;

end if;

end loop ;
end loop;



Put ("The smallest distace is : ");
Put (SmallestDistance, 8, 3, 0);
New_line;
Put ("the smallest distance lies on : ");
new_Line;
New_Line;
Put ("Line 1 : ");
Put (Point1, 8, 3, 0);
Put (Point1a, 8, 3, 0);
new_line;
Put ("Line 2 : ");
Put (Point2, 8, 3, 0);
Put (point2a, 8, 3 ,0);

end main;