Get selected row column values from Interactive Grid in Oracle APEX

1. How to fetch the selected row in apex interactive gird region column value?
2. We used javascript for above question.

Eg.var i,  get_valueids = ":", I_SELECTED_VAL,

model = this.data.model;

for ( i = 0; i < this.data.selectedRecords.length; i++ ) {

  I_SELECTED_VAL = model.getValue( this.data.selectedRecords[i], "GRADECODE");

   get_valueids += model.getValue( this.data.selectedRecords[i], "GRADECODE") + ":";

}

apex.item( "P1_GRADECODE" ).setValue ( I_SELECTED_VAL);