Required library edition: 
Required library file: dhtmlxgrid.js
selects row by ID
row_id - row id
preserve - {true|false} preserve previously selected (optional, false by default). Multi select mode should be enabled.
show - true/false - scroll row to view (optional, true by default)
call - true if to call onRowSelect function (optional, false by default)
//minimal parameters set
mygrid.selectRowById('row1');
//maximal parameters set
mygrid.selectRowById('row1',true,true,true);
Please make sure that necesary row is loaded before calling this method.
See also: selectRow, selectAll