selected value of multi select lookup not displaying in form

I have created multi select lookup. It is working fine but when I select value it does not display value on form. below is my screen shot 

here is my lookup code

public void lookup()
{
   Query query = new Query();
    QueryBuildDataSource queryBuildDataSource;
    QueryBuildRange queryBuildRange;
    SysTableLookup sysTableLookup;

    str   ItemCategoryCodeforlockup = RNI_Product.valueStr();
    if(ItemCategoryCodeforlockup)
    {
        queryBuildDataSource = query.addDataSource(tableNum(SL_ItemCatSubType));
        queryBuildDataSource.addRange(fieldNum(SL_ItemCatSubType,RNI_LINEOFPRODDESCRIPTION)).value(ItemCategoryCodeforlockup);
        msCtrl = SysLookupMultiSelectCtrl::constructWithQuery(this.formRun(),this,query);
    }
}

public boolean modified()
{
       boolean ret;
container c,v;
int i;
ret = super();

if (ret)
{
c = msCtrl.get();  // get RecIds of the selected rows
v = msCtrl.getSelectedFieldValues(); // get actual value of the selected rows

for (i = 1; i <= conLen(c);i++)
    {
    //info(conPeek(c,i));
    //info(conPeek(v,i));

    }
}

return ret;
}