int width = ((alnumARG *)argp)->width;
int width = ((const alnumARG *)argp)->width;
static bool Check_AlphaNumeric_Field(FIELD * field, const void * argp){  int width = ((alnumARG *)argp)->width;  unsigned char *bp  = (unsigned char *)field_buffer(field,0);  int  l = -1;  unsigned char *s;  while(*bp && *bp==' ')     bp++;  if (*bp)    {      s = bp;      while(*bp && isalnum(*bp)) 	bp++;      l = (int)(bp-s);      while(*bp && *bp==' ') 	bp++;    }  return ((*bp || (l < width)) ? FALSE : TRUE);}