Analytical ordered function to get the first row in window - response (1) by abin

I think the table data in my previous post didnt come as expected, here is the table, result column is what I expect as output.
 

Column1

Column2

Column3

Column5

Result

Key0

3/8/2011 13:00

Entry New

KJLUONMP

Key0

3/8/2011 14:00

Change New

KJLUONMP

Key1

3/8/2011 16:00

Transfer

KJLUONMP

Key1

3/8/2011 19:00

Change out

KJLUONMP

Key1

3/24/2011 7:00

Change In

KJLUONMP

Key1

3/24/2011 9:00

Return

XCDVGHNJ

Key1

4/10/2011 3:43

Load

XCDVGHNJ

KJLUONMP

Key1

4/10/2011 4:43

Return

XCDVGHNJ

 
Abin