Problem in crystal reports

[bharathi228]

hi,

iam working with crystal reports.in my database table i have a
columns like dtmtime,paramet er_index


dtmtime parameter_index status

1/2/2006 11 SVC
4/2/2006 12 COS
6/2/2006 11 SVC
7/2/2006 11 UNK
12/2/2006 12 SVC


in my report grouping field is parameter_index

i want to display startime,endtim e for each parameter_index

here starttime for parameter_index 11 is 1/2/2006
End time ,, 11 is 7/2/2006

Startime for ,, 12 is 4/2/2006
endtime for ,, 12 is 12/2/2006


for this iam using formula fields
minimum(dtmtime ),maximum(dtmti me)

but they give startdate for all param index is 1/2/2006
and end date is 12/2/2006

how to write formula with condition.

and my another problem is i have a subreport in this main report

in subreport i have to display Status descriptions
and toal hours

here total hours calculation is find the days between startdate and enddate of
a parameter_index and calucalte total hours in those days for each status.


for this purpose i want to pass startdate,endda te from mainreport to subreport

so iam using change report links and startime,endtim e fileds linking to main report to subreport.

here the problem is status descriptions are not displayed.why because when iam linking with mainreport to subreport it is displying
only report fields.



please any one help me with this problems.

iam struggle with these problems from 3 days.


pls pls pls any one give the solution for this