I just found something that I just can't find the reason. I have a terrible slowdown in one of my .NET application.

If I have this:

                        If cCurrentField = "No_Claim" Then
                            lcHtml = lcHtml + "&ClaimNo=" + Trim(oRow("No_Claim")) + "&MitTelAI=" + _
                             LTrim(Str(oRow("AI"))) + "&Hd=1>"
                        End If

as part of a loop which is executed 200 times, it will take one second to execute the loop 200 times.

But, if I have this:

                        If cCurrentField = "No_Claim" Then
                            lcHtml = lcHtml + "&ClaimNo=" + Trim(oRow("No_Claim")) + "&MitTelAI=" + _
                             LTrim(Str(oRow("AI"))) + "&Hd=1>" + "&ClaimNo=" + Trim(oRow("No_Claim")) + "&MitTelAI=" + _
                             LTrim(Str(oRow("AI"))) + "&Hd=1>" + "&ClaimNo=" + Trim(oRow("No_Claim")) + "&MitTelAI=" + _
                             LTrim(Str(oRow("AI"))) + "&Hd=1>" + "&ClaimNo=" + Trim(oRow("No_Claim")) + "&MitTelAI=" + _
                             LTrim(Str(oRow("AI"))) + "&Hd=1>" + "&ClaimNo=" + Trim(oRow("No_Claim")) + "&MitTelAI=" + _
                             LTrim(Str(oRow("AI"))) + "&Hd=1>" + "&ClaimNo=" + Trim(oRow("No_Claim")) + "&MitTelAI=" + _
                             LTrim(Str(oRow("AI"))) + "&Hd=1>" + "&ClaimNo=" + Trim(oRow("No_Claim")) + "&MitTelAI=" + _
                             LTrim(Str(oRow("AI"))) + "&Hd=1>" + "&ClaimNo=" + Trim(oRow("No_Claim")) + "&MitTelAI=" + _
                             LTrim(Str(oRow("AI"))) + "&Hd=1>"
                        End If

as part of a loop which is executed 200 times, it will take 7 seconds to execute the loop 200 times.

What is going on? Why is it that simply adding a longer string causes the process to crawl?