I've a field named Department on a form for which I override a lookup method on datasource 'Department' field. The code is as

public void lookup(FormControl _formControl, str _filterStr)
{
Query query = new Query();
QueryBuildDataSource queryBuildDataSource;
QueryBuildRange queryBuildRange;
SysTableLookup sysTableLookup = SysTableLookup::newParameters(tableNum(OMOperatingUnit), _formControl, true);
sysTableLookup.addLookupField(fieldNum(OMOperatingUnit, Name));
sysTableLookup.addLookupField(fieldNum(OMOperatingUnit, OMOperatingUnitNumber));
queryBuildDataSource = query.addDataSource(tableNum(OMOperatingUnit));
queryBuildDataSource.addRange(fieldNum(OMOperatingUnit, OMOperatingUnitType)).value(queryValue(OMOperatingUnitType::OMDepartment));
sysTableLookup.parmQuery(query);
sysTableLookup.performFormLookup();
}
I wish to know that how would i resize my auto lookup form not manually, as this:

Currently, it displays this way:
