Drawing Call Flow with sequence Diagram leads to ambiguity

Question

I want to draw a Sequence Diagram Where

A -> B.run()
B.run() -> B.m1()
B.m1() -> B.m2()

So far I've come up with these.

http://i51.tinypic.com/eja5bl.jpg http://i52.tinypic.com/1449s3.jpg

But Here I cannot mention it clearly that B.m2() is called by B.m1() Rather it looks like B.run() Calls both B.m1() and B.m2() serially.

------------- EDIT ----------------

This is What I Currently have drawn http://i55.tinypic.com/21276kk.jpg

Well Is my Current Diagram Okay ?? What I want is this. (Call Flow)

SpiritAdapter -> SpiritEngine::run(spirit:string, method:string, args[])
SpiritEngine::run(spirit:string, method:string, args[]) -> SpiritEngine::executeLogic(spirit:string, method:string, args[])
SpiritEngine::executeLogic(spirit:string, method:string, args[]) -> SpiritEngine::spirit(spirit:string, method:string, args[])
SpiritEngine::spirit(spirit:string, method:string, args[]) -> new SpiritAbstractor
SpiritEngine::executeLogic(spirit:string, method:string, args[]) -> SpiritAbstractor::method(args)
SpiritEngine::run(spirit:string, method:string, args[]) -> SpiritEngine::storeXDO()

Answer 1

You can add a small bar over B.m2() and then place a self pointing arrow, for example.

Self message vs recursive call

Answer 2

The uml spec allows for a nested call to be shown visually: the called lifeline should be overlaid on the calling lifeline. See e.g. determineAvailableReport() call in this example.

Whether your tool supports it of course is another matter...