method seekRelative

This method changes the position of the attached stream relative to its current position by the amount specified in offset. A negative number can be used to move backwards from the current position.

var memStreamObj = shell.serviceManager.basics.memoryStream;
var streamWriterObj = shell.serviceManager.basics.rawStreamWriter;
var streamReaderObj = shell.serviceManager.basics.rawStreamReader;

memStreamObj.size = 1024;
streamWriterObj.stream = memStreamObj;
streamWriterObj.seekToStart();
streamWriterObj.writeInt32(42);
streamWriterObj.writeInt32(41);
streamWriterObj.writeInt32(40);

//this will read back 42 41 41 40 by using seekRelative    
streamReaderObj.stream = memStreamObj;
streamReaderObj.seekToStart();
alert(streamReaderObj.readInt32());
alert(streamReaderObj.readInt32());

//4 is the size of a int32
memStreamObj.seekRelative(-4);
alert(streamReaderObj.readInt32());
alert(streamReaderObj.readInt32());

memStreamObj.close();