Создание графического интерфейса выпадающем списком

int pos_size_button0[1][4];
string text_button0[1];
int flag_button0[1];

pos_size_button0[0][0]=64; pos_size_button0[0][1]=193; pos_size_button0[0][2]=100; pos_size_button0[0][3]=20;
text_button0[0]="Кнопка 0";

//////////

int pos_size_combo0[2][4];
string text_combo0[2][3];
int strok_combo0[2];
int flag_combo0[2];

pos_size_combo0[0][0]=67; pos_size_combo0[0][1]=53; pos_size_combo0[0][2]=100; pos_size_combo0[0][3]=80;
pos_size_combo0[1][0]=63; pos_size_combo0[1][1]=111; pos_size_combo0[1][2]=100; pos_size_combo0[1][3]=80;
strok_combo0[0]=3; strok_combo0[1]=3;
text_combo0[0][0]="Список 0"; text_combo0[0][1]="Список 1"; text_combo0[0][2]="Список 2";
text_combo0[1][0]="спис 1"; text_combo0[1][1]="спис 2"; text_combo0[1][2]="спис 3";
flag_combo0[0]=0; flag_combo0[1]=0;

//////////

createdialog(0, BUTTON, #pos_size_button0[0][0], #text_button0[0], #flag_button0[0] |
COMBO, #pos_size_combo0[0][0], #text_combo0[0][0], #strok_combo0[0], #flag_combo0[0]);
//////////

showdialog(0, "Диалог", 558, 234, 250, 300, 1, 1);
//////////

while(flag_button0[0]!=1) sleep(100);
flag_button0[0]=0;


int a,b;


if(flag_combo0[0]==0) a=1;
if(flag_combo0[0]==1) a=2;
if(flag_combo0[0]==2) a=3;

if(flag_combo0[1]==0) b=1;
if(flag_combo0[1]==1) b=2;
if(flag_combo0[1]==2) b=3;

destroydialog(0);

messagebox(format(a)+" "+format(b));