> I have XML document with an element having comma seperated 
> values as below 
> <RowKey>JAN,FEB,MAR,APR,MAY,JUN,JUL,AUG,SEP,OCT,NOV,DEC,YTD</RowKey>
> 
> I need to loop through the values.

In XSLT 1.0, write a named template that extracts the first value using
substring-before($param, ','), and then calls itself recursively to process
the rest of the string by passing substring-after($param, ',') as the
parameter value. The recursion should terminate when the string contains no
commas. 

If you don't want to write it yourself, download the str:tokenize template
from www.exslt.org - it does just this.

Regards,

Michael Kay
http://www.saxonica.com/
http://twitter.com/michaelhkay