First test waitForNotValue
Test WaitForValueNot
open ../tests/html/test_async_event.html  
assertValue theField oldValue
click theButton  
assertValue theField oldValue
waitForNotValue theField regexp:oldValu[aei]
verifyValue theField newValue

Now test waitForTextNot
assertText theSpan Some text
click theSpanButton  
assertText theSpan Some text
waitForNotText theSpan regexp:Some te[xyz]t
verifyText theSpan Some new text