Once a table's definition has been loaded;

t=new TableDef()

t.tableName="tablename"

t.load()

Use the following syntax;

To view the size of the index array

?t.indexes.size // Where t is an instance of the TableDef object

To numerically loop through the array's indexnames

?t.indexes[n].indexname // Where n is a number from 1 to the value of "t.indexes.size"