Iterate Form Fields

string sDiagCode = "";
int nDiagCode = 0;

NameValueCollection submittedValuesCollection = Request.Form;
foreach (string key in submittedValuesCollection.AllKeys)
	{
		if (key.Replace("ctl00$MidContentPlaceHolder$", "").Contains("chk_icd9_"))
			{
				if (submittedValuesCollection[key] == "on")
					{
						nDiagCode = nDiagCode + 1;
						sDiagCode += key.Replace("ctl00$MidContentPlaceHolder$chk_icd9_", "") + "|";
					}
			}
	}

foreach (string key in Request.Form.Keys)
	{
		if(key.Replace("ctl00$MidContentPlaceHolder$", "").Contains("additionaldiags_"))
			{
				nDiagCode = nDiagCode + 1;
				sDiagCode += Request.Form[key].Replace(".","").Trim() + "|";
			}
	}