Write a program in pascal to solve a quadratic equation

Program p1;
var a,b,c,d : integer; {i presume you give integer numbers for the values of a, b, c }
     x1, x2 : real;
begin 
write('a='); readln(a);
write('b='); readln(b);
write('c=');readln(c);
d:=b*b - 4*a*c
if a=0 then x1=x2= - c/b
          else
if d>0 then begin 
                 x1:=(-b+sqrt(d)) / (2*a);
                 x2:=(-b - sqrt(d))/(2*a);
                end;
          else if d=0 then x1=x2= - b /(2*a)
                           else write ("no specific solution because d<0");
writeln('x1=', x1);
writeln('x2=',x2);
readln;
end.