hiddenfield

Hi,
In my application  want to calculate total of all hidden fields.If any textbox   value chages hidden value is  comes to that value .
sundayhiddenfield (03:00:00)
mondayhiddenfield(03:00:00)
tueshiddenfield(03:00:00)
wedhiddenfield(01:00:00)
.
.
onsitetextbox (10:00:00)before
 
if user want to update  monday
sundayhiddenfield (03:00:00)
mondayhiddenfield(01:00:00)//changed
tueshiddenfield(03:00:00)
wedhiddenfield(01:00:00)
.
.
onsitetextbox (01:00:00)//expected output 08:00:00
 
 
TimeSpan sunOnsitelHrs = !string.IsNullOrEmpty(txt_hdSunOnsiteHrs.Value) ? TimeSpan.Parse(txt_hdSunOnsiteHrs.Value) : TimeSpan.Zero; TimeSpan monOnsiteHrs = !string.IsNullOrEmpty(txt_hdMonOnsiteHrs.Value) ? TimeSpan.Parse(txt_hdMonOnsiteHrs.Value) : T ...