Listview Refresh?

Hi,

After inserting column into the lsitview, I want to know how can I delete this and then inserting another column...

I insert column like this:
----------------------------------------
LV_COLUMN col;

col.mask=LVCF_FMT|LVCF_SUBITEM|LVCF_TEXT|LVCF_WIDTH;
col.fmt=LVCFMT_LEFT;

for (int yk=0;yk5;yk++)
{
       col.iSubItem=yk;
       col.pszText="Testing";
       col.cx=120;
       wndList.InsertColumn(yk,&col);
}

CHeaderCtrl* pHeader1 = (CHeaderCtrl*)wndList.GetDlgItem(0);

for (int kk=0;kk<5;kk++)
{
      pHeader1->DeleteItem(0);
}

for (yk=0;yk<NumField;yk++)
{
     col.iSubItem=yk1;
     col.pszText="Second";
     col.cx=120;
    wndList.InsertColumn(yk,&col);
}

----------------------------------------

After doing this, I found even the width of my listview is enough to display the five column, the horizontal scroll bar is still appeared.

I think I cannot remove the five  columns added at the first time.
Thus, I want to know how can I remove the column added and insert another new columns in my listview.

I hope the horizontal scroll bar will only be appeared if the width of the listview is not enoguh to display the five columns I added each time.

What mistake had I made?
Thanks!!!