checking variable for no value

Heres the deal, its a windows program btu it more involves a C++ problem.

Basically, the user has a dialog box open and they can input numbers and text, however, i want to make it so they HAVE to input something before clicking "ok" in order for it to process. Now, im a big OOP programmer in the past so i thought this method would work, any other method i try gets general errors.

Code:

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case IDOK:
GetDlgItemText(hwnd, G_COLOR, szGlowColor, 7);
GetDlgItemText(hwnd, G_STRENGTH, szGlowStrength, 3);
GetDlgItemText(hwnd, G_TEXT, szGlowString, 700);
if(!szGlowColor) {
 MessageBox(hwnd, "You must enter in a value for the color", "Error", MB_OK);
 return FALSE;
} else {
 if(!szGlowStrength) {
  MessageBox(hwnd, "You must enter in a value for the strength", "Error", MB_OK);
  return FALSE;
 } else {
  SendMessage(hEdit, EM_REPLACESEL, (WPARAM) 0, (LPARAM) "<table style='Filter: Glow(Color=#");
  SendMessage(hEdit, EM_REPLACESEL, (WPARAM) 0, (LPARAM) szGlowColor);
  SendMessage(hEdit, EM_REPLACESEL, (WPARAM) 0, (LPARAM) ", Strength=");
  SendMessage(hEdit, EM_REPLACESEL, (WPARAM) 0, (LPARAM) szGlowStrength);
  SendMessage(hEdit, EM_REPLACESEL, (WPARAM) 0, (LPARAM) ")'><tr><td>");
  SendMessage(hEdit, EM_REPLACESEL, (WPARAM) 0, (LPARAM) szGlowString);
  SendMessage(hEdit, EM_REPLACESEL, (WPARAM) 0, (LPARAM) "</td></table>");
  EndDialog(hwnd, 0);
  return TRUE;
  }
}
return FALSE;
break;

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i need to check if szGlowColor and szGlowStrength have a value entered in them, doesn't matter if its numerical or alphabetical, just need to check is somethings in there.

(EDIT: took out the formatting for horizontal scrolling sakes)

Hi, can you use the old strlen() function? Or, since you're doing it in C++, turn the results into temp string objects (STL) and ask them if they are null?

(sorry if it's a dumb answer, but I'm fairly new to C++!)

Nick.

I believe GetDlgItemText returns the number of bytes copied:

Code:

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//this could work:
if (GetDlgItemText(/*...*/)==0)
 //Cannot continue

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Quote:

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Originally posted by NickESP
sorry if it's a dumb answer...

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I'm impressed that you deciphered a question :)

gg

Quote:

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Originally posted by JaWiB
I believe GetDlgItemText returns the number of bytes copied:

Code:

---

//this could work:
if (GetDlgItemText(/*...*/)==0)
 //Cannot continue

---

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Thanks JaWiB, that did the trick, it now checks if something is entered, awsome.

Again, thanks guys.