why does this crash? Or how would I make it work?

Code:

---

void __fastcall TForm1::Button1Click(TObject *Sender)

{
int i,d,z;
char c[5];

 for(i=0;i<=7;i++) {
        z++;
        c[i]= Edit1->Text[z]; // c... Data being generated
          }

      for(d=0;d<=6;d++) {

            Edit2->Text = Edit2->Text+ c[d]+"";
      // WriteFile( HdComm, &c[d], 1, &RealNum, NULL ); //c...is the data
        }
      }

---

I would llike to send individual bytes through COM1 to a µProcessor , being able to either get the ASCII value orcthe character .

Any help would be appreciatted.

As Salem points out, the buffer size.

and int 'z' is never initialised (and seems redundant).

The amount of data in the edit buffer is never checked (to ensure is even exists or will fit into the buffer).