One of the problems with doing error checking the way it was demonstrated in part one is when the user is redirected back to the input page do to an error all their inputted information is gone. This can be frustrating to the user if they just type in a lot of information and because they forgot one item they have to retype it all over again.

There is many different solution to fix this problem. One is to only use one web page not two. In part one you built an input page that passes all the information to a process page to do the error checking. You can combine both these pages into one. When the user enters in their data and clicks on the submit button all the information is pass to itself, not another page. In short it calls itself. You will have all your error checking code at the top of the web page to process the data. If it passes the error checking your code will redirect the user to the next page. Else if there is an error, you are already on the original page thus you just have to display an error message and display the page with their data again.

There is many little tips in order to do error checking these way. This demo will show you them.

The first one is how do you get the page only to run the error checking when the page calls itself. If you just copy your error checking from part one and paste it at the top of the page it will run every time you try to display the page. What will happen is the first time the page is loaded the page will have no data thus the error checking will think it is missing required information. The page will display your error message. You have to get the page only to run the code when it calls itself. To do this you will need a way do determine when to run the code and when not too. The easiest way to do this is by using a hidden HTML input tag on your page.

Example:
      <INPUT type="hidden" name="action" value="check">

What will happen is when the page calls itself there will be a variable called action with the value check in existents. If the page doesn't call itself, [Example: first time it loads] there will be no variable called action in existents. For all you have to do is wrap all your error checking code inside of a if statement that only runs if the variable exist.

Example:
     Dim strAction
     strAction = request.form("action")

     if LCase(strAction) = "check" then
          Do your error checking
     end if