The DDV (Dialog Data Validation) functions check the range of input data. These are the list of available DDV functions:
DDV_MaxChars() Verifies that the length of CString is less than or equal to the Max value.
DDV_MinMaxByte() Verifies that the BYTE value is between Min and Max.
DDV_MinMaxDouble() Verifies that the double value is between Min and Max.
DDV_MinMaxDWord() Verifies that the DWORD value is between Min and Max.
DDV_MinMaxFloat() Verifies that the float value is between Min and Max.
DDV_MinMaxInt() Verifies that the int value is between Min and Max.
DDV_MinMaxLong() Verifies that the long value is between Min and Max.
DDV_MinMaxUInt() Verifies that the UINT value is between Min and Max.

The validation of DDX variables takes place all at once when the user chooses to accept the entries in the dialog box.