CloseSelect() method in form level + ax 2012

Requirement like creation of filter on lookup first when i click lookup it is not allowing select another field means it is not waiting at all...

i check out many methods and finally i come to know that is we can use closeselect()  method.

void closeSelect(str p1)
{
    if (canSelect)
    {
        super(p1);
    }
    else
    {
        if (mustKeepFormOpened)
        {
            mustKeepFormOpened    = false;
            canSelect             = true;
        }
    }
}