Кнопка run неактивна

//---------------------------------------------------------------------------
 
#include <vcl.h>
#include <stdio.h>
#include <conio.h>
#include <math.h>
#include <stdlib.h>
#include <string.h>
#pragma hdrstop
#include "Unit1.h"
#pragma package(smart_init)
#pragma resource "*.dfm"
TForm1 *Form1;
int B;
 
double f(double x)
{
 double z;
 z=pow(x,3)-2*pow(x,2)+x-3;
 return z;
}
 
 
double df(double x)
{
 double z;
 z=3*pow(x,2)-4*x+1;
 return z;
}
 
double d2f(double x)
{
 double z;
 z=6*x-4;
 return z;
}
 
double hord(double a, double b, double *e, int B,int *N,int *err)
{
 double q;double x;
 double z=(b-a)/(f(b)-f(a));
 if(f(a)*d2f(a)>0)
  q=b;
  else q=a;
 int i=1;
 *err=1;
 while(i<B)
 {
   x=q-f(q)*z;
   if(fabs(x-q)<*e)
    {
     *N=i;
     i=B;
     *e=f(x);
     *err=false;
    }
   else
    {
     i=i+1;
     q=x;
    }
  }
 return x;
}
 
double cas(double a, double b, double *e, int B,int *N,int *err)
{
 double x1;double x;
 if(f(a)*d2f(a)>0)
  x1=a;
  else x1=b;
  int i=1;
  *err=1;
 while(i<B)
 {
   x=x1-f(x1)/df(x1);
   if(fabs(x-x1)<*e)
    {
     *N=i;
     i=B;
     *e=f(x);
     *err=false;
    }
   else
    {
     i=i+1;
     x1=x;
    }
  }
 return x;
}
 
//---------------------------------------------------------------------------
__fastcall TForm1::TForm1(TComponent* Owner)
        : TForm(Owner)
{
 Label2->Caption="pow(x,3)-2*pow(x,2)+x-3=0";
 B=atoi(Edit4->Text.c_str());
}
//---------------------------------------------------------------------------
 
 
void __fastcall TForm1::Button2Click(TObject *Sender)
{
Form1->Close();
}
//---------------------------------------------------------------------------
 
void __fastcall TForm1::RadioButton4Click(TObject *Sender)
{
Edit5->Text="0.000001";
}
//---------------------------------------------------------------------------
 
void __fastcall TForm1::RadioButton3Click(TObject *Sender)
{
 Edit5->Text="0.001";
}
//---------------------------------------------------------------------------
 
void __fastcall TForm1::Button1Click(TObject *Sender)
{
 int N=0; int err=0; double x;
 double a=atof(Edit2->Text.c_str());
 double b=atof(Edit3->Text.c_str());
 double e=atof(Edit5->Text.c_str());
 if (!isdigit(Edit3->Text.c_str()[0])&&Edit3->Text.c_str()[0]!='-'||!isdigit(Edit2->Text.c_str()[0])&&Edit2->Text.c_str()[0]!='-'||!isdigit(Edit5->Text.c_str()[0])||!isdigit(Edit4->Text.c_str()[0]))
 {
  Application->MessageBox("vvedite chislennoe znachenie","Oshibka",MB_OK);
  return ;}
 if(RadioButton1->Checked==true)
   x=hord(a,b,&e,B,&N,&err);
  else x=cas(a,b,&e,B,&N,&err);
 if(err)Application->MessageBox("Previsheno chislo iteratciy","Oshibka",MB_OK);
 Edit6->Text=e;
 Edit7->Text=N;
 Edit1->Text=x;
}
//---------------------------------------------------------------------------
 
void __fastcall TForm1::Edit4Change(TObject *Sender)
{
 B=atoi(Edit4->Text.c_str());
}
//---------------------------------------------------------------------------