Start with the debugger: put a breakpoint on the line
sqlCmd.ExecuteNonQuery();
and run your code in the debugger. When it stops at the breakpoint, look at the content of the variables you have just set as parameters, paying attention to
<pre>txtEvTime.Text</pre>
What does it contain? Is it a valid time in text format? If not, why not?
If it is, then step over the ExecuteNonQuery instruction and look at what happens. Does it go to the catch block? If so, look at the exception in
ex
and find out why it went there - there is a lot =of info in there that can help you.
Does it even reach the breakpoint? Me, I'd be very suspicious of this line:
if (btnEvSave.Text == " Save")
Which looks very dodgy...
We can't do any of this for you - we don't have any access to your code, or data, or SP, or ... so you will have to gather information for yourself!