Classic ASP Discussion - QueryString parameters

Response.Write(vbCrLf & " <a href=""" & thisFile & "?" & Request.ServerVariables("QUERY_STRING") & "")
If LCase(Request.QueryString("shw")) <> "cds" Then Response.Write("&shw=cds")
Response.Write(""" class=""link"">Show all codes</a>")

Private Function SmartQuery(ByVal strquerystrings, ByVal strValues)

dim strQuerystring
dim i
dim saryquerystrings
dim strquerystrings
dim strValues
dim saryValues

strQuerystring = "&" & Request.ServerVariables("QUERY_STRING")

saryquerystrings = Split(strquerystrings, "&")
saryValues = Split(";" & strValues, ";")

FOR i = 0 to unbound(saryquerystrings)

if not intstr(1, LCase(strQuerystring) , LCase(saryquerystrings (i)) & "=" & LCase(saryValues(i)) , vbTextCompare) then

strQuerystring = strQuerystring & "&" & saryquerystrings (i) &"=" & saryValues(i) & ""

end if

next

'Return Function
SmartQuery = strQuerystring
End Function

Private Function SmartQuery(ByVal strquerystrings, ByVal strValues)

dim strQuerystring
dim i
dim saryquerystrings
dim strquerystrings
dim strValues
dim saryValues
dim strTempQueryValue

strQuerystring = "&" & Request.ServerVariables("QUERY_STRING")

saryquerystrings = Split(strquerystrings, "&")
saryValues = Split(";" & strValues, ";")

FOR i = 0 to unbound(saryquerystrings)

' delete the parameter and value from the querystring
if intstr(1, LCase(strQuerystring) , LCase(saryquerystrings(i)) &"=", vbTextCompare) then

strTempQueryValue = request.querystring(saryquerystrings(i))
strQuerystring = replace(LCase(strQuerystring), Lcase("&" & saryquerystrings(i)) & "=" & strTempQueryValue , "")

strQuerystring = replace(LCase(strQuerystring), Lcase("?" & saryquerystrings(i)) & "=" & strTempQueryValue &"&" , "?")

END IF

' insert the new parameter
strQuerystring = strQuerystring & "&" & saryquerystrings (i) &"=" & saryValues(i) & ""

next

'Return Function
SmartQuery = strQuerystring
End Function

<%
thisFile = "fun.asp"

Response.Write(vbCrLf & "<a href=""" & thisFile & "?op=ab&bid=33&cid=21&bp=16&shw=ops"">Lotsof</a> ")

Response.Write(vbCrLf & "<a href=""" & thisFile & """>None</a> ")

Response.Write(vbCrLf & "<a href=""" & thisFile & "?" & sQuery("shw=cds") & """>Query</a>")

'// [=======================================================]
'// [=| sQuery |=]
'// [=======================================================]
Function sQuery(ByVal strMyQuery)

Dim strQueryFull, arrVarAndValue, arrVar, arrMyVar, arrMyValue, query, var

strQueryFull = Request.ServerVariables("QUERY_STRING")

arrVarAndValue = Split(strQueryFull, "&")

'// Get my variable not value with arrMyVar(0)
arrMyVar = Split(strMyQuery, "=")

For query = 0 to UBound(arrVarAndValue)
 If LCase(arrVarAndValue(query)) = strMyQuery Then strMyQuery = ""
 Response.Write(vbCrLf & "Query: " & arrVarAndValue(query) & " ")

 arrVar = Split(arrVarAndValue(query), "=")

 For var = 0 to UBound(arrVar)
 If var Mod 2 Then Response.Write(vbCrLf & "Var only: " & arrVar(var Mod 1) & " ")
 Next

 Response.Write(" ")
Next

If strMyQuery = "" Then
 sQuery = strQueryFull
ElseIf strQueryFull = "" Then
 sQuery = strMyQuery
Else
 sQuery = strQueryFull & "&" & strMyQuery
End If

End Function
'// --------------------------| End of function: sQuery
%>

This code should solve all your problems, plus. The first method depends on the other two, which are equally useful on their own. You'll need to remove the &nnbs p; that the board added in the one function.

/// <summary>
/// Appends string items together with a specific string separating the items. Unless false is
/// specified for AppenWhenListItemIsEmpty, an empty ListItem item will be appended. If true is
/// specified for AppendWhenListItemIsNull, a null ListItem will be appended as an empty string.
/// </summary>
/// <param name="List">The list to append to</param>
/// <param name="ListItem">The item to be appended to the list</param>
/// <param name="ListItemSeparator">The string that will separate the list from the new item</param>
/// <param name="AppendWhenListItemIsNull">
/// If true, a null ListItem should be appened as an empty string.
/// If false, a null ListItem will cause the List to be returned as-is without any modification.
/// </param>
/// <param name="AppendWhenListItemIsEmpty">
/// If true, an empty ListItem should be appened.
/// If false, an empty ListItem will cause the List to be returned as-is without any modification.
/// </param>
/// <returns>A separated string</returns>
public static string AppendListItems(string List, string ListItem, string ListItemSeparator, bool AppendWhenListItemIsNull, bool AppendWhenListItemIsEmpty)
{
 string ret = string.Empty;

 if ((!AppendWhenListItemIsNull && ListItem == null) || (!AppendWhenListItemIsEmpty && ListItem.Trim().Length == 0))
 {
 ret = List;
 }
 else
 {

 // Validate the ListItemSeparator argument
 if (ListItemSeparator == null)
 {
 &nbs p; throw new System.ArgumentNullException("ListItemSeparator");
 }

 // Clean the ListItem argument
 if (ListItem == null)
 {
 &nbs p; ListItem = string.Empty;
 }

 // Append the list items
 if (List == null || List == string.Empty)
 {
 &nbs p; ret = ListItem;
 }
 else
 {
 &nbs p; if (List.EndsWith(ListItemSeparator))
 &nbs p; {
 &nbs p; ret = List + ListItem;
 &nbs p; }
 &nbs p; else
 &nbs p; {
 &nbs p; ret = List + ListItemSeparator + ListItem;
 &nbs p; }
 }
 }

 // Return the result
 return ret;
}

/// <summary>
/// Appends a name and value onto a querystring as a name=value pair.
/// </summary>
/// <param name="QueryString">The Querystring to add the items to</param>
/// <param name="Name">The Name part of the pair</param>
/// <param name="Value">The Value part of the pair</param>
/// <param name="ReplaceNameValuePairIfNameAlreadyPresent">Whether or not to replace the
/// name value pair with the new name value pair if the name already exists</param>
/// <param name="AppendValueToNameIfNameAlreadyPresent">Whether or not to include the
/// value as a subvalue of Name if Name already exists in the querystring. If
/// ReplaceNameValuePairIfNameAlreadyPresent is true, this value is ignored</param>
/// <returns></returns>
public static string AppendNameValuePairToQueryString(string QueryString, string Name, string Value, bool ReplaceNameValuePairIfNameAlreadyPresent, bool AppendValueToNameIfNameAlreadyPresent)
{
 string ret = string.Empty;

 if (!(Name == null || Value == null || Name.Trim().Length ==0 || Value.Trim().Length == 0))
 {
 // Clean the querystring
 if (QueryString == null)
 {
 &nbs p; QueryString = string.Empty;
 }
 else
 {
 &nbs p; QueryString.Trim(' ', '&');
 }

 bool nameAlreadyPresent = (QueryString.IndexOf("?"+Name+"=") >= 0 || QueryString.IndexOf("&"+Name+"=") >= 0);

 // Add the value onto the end of the existing name=value pair with a comma between
 // the added value and the previous value
 if (nameAlreadyPresent && (ReplaceNameValuePairIfNameAlreadyPresent || AppendValueToNameIfNameAlreadyPresent))