Or try this one for displaying both inches and mm:

script: /* Convert selected dimension to mixed inches and mm */ if ( moi.geometryDatabase.units != 'Inches' ) { moi.ui.alert( 'error - main units not inches' ); } else { var dims = moi.geometryDatabase.getSelectedObjects().getLinearDimensions(); for ( var i = 0; i < dims.length; ++i ) { var dim = dims.item(i); dim.text = dim.evalText() + ' [' + moi.ui.formatNumber( dim.numericValue * 25.4, dim.numDecimalPlaces ) + ' mm]'; } }

That will set something displaying as 1" to read 1" [25.4 mm]

- Michael