Alternate background colour for grouped fields

[ericvanrheenen]

Hello,

I have a report with 9 fields in the detail band.  Now i want to change the background colour (alternated) when the value of a field changes.  The number of identical fields (field3 in example below) is not constant.
Example:
field1  field2 field3 = "aaa" field4 field5
field1  field2 field3 = "aaa" field4 field5
field1  field2 field3 = "bbb" field4 field5
field1  field2 field3 = "ccc"  field4 field5
field1  field2 field3 = "ddd" field4 field5
field1  field2 field3 = "ddd" field4 field5
 

Please advice to do this.
 

[reportdev]

check this wiki page

http://community.jaspersoft.com/wiki/getting-previous-records-value-calculation-variables-etc