Hi All,

I have a piece of code which sends an email out to a customer after buying an item online. The problem is, sometimes, the customer receives the mail several times.

Is there a way to make sure the code executes only once?

Thanks.:(

It sounds like to me that sometimes impatient customers are clicking your submit button multiple time which causes multiple emails to be generated. When the final submission is made disable the submit button with java script so they cant hit the button again. Or if you want to carry it out with asp on the page the is submitting the email do something like this.

'Top of the page that has the CDO mail
if request.cookies("error") ="YES" then
   response.redirect "somepage.asp"
end if
response.cookies("error")="YES"

Earl
www.jhdesigninc.com

Simply do a response.redirect after the mail is sent - perhaps to a thank you your email is sent page

Wind is your friend
Matt

Hey Matt,
If there is alot of processing going on on the page that is sending the email there may be some lag in the redirect and the user will still be able to "mash" the submit button sending multiple requests before the page is processed.

Originally I said set a cookie but looking over some of my older code I see I have used a javaScript solution the majority of the time to fix this issue.

<script language="JavaScript" type="text/JavaScript">
    //some validation

    function validate(form ){
        if ( form.textfield.value=="" ){
            alert("You must enter a value")
            return false;
        }else{
            form['Submit'].disabled=true;
            return true;
        }
    }
</script>

<form name="form1" method="post" action="page.asp" >
  <input type="text" name="textfield">

  <input type="button" name="Submit" value="Submit" onClick="return validate(this.form);this.submit();">

</form>

Earl
www.jhdesigninc.com

Providing the redirect is placed correctly I do not believe its possible for any more than one email to be sent. Although I do strongly advise client side form validation I would only use a client side solution as a last resort to ensure only one email is sent - I wouldnt rely on cookies.

Wind is your friend
Matt

Hey Matt,
I can recreate this and have had issues with multiple clients submissions using a redirect. I found that disabling the submit button is most often the way to go. Impatient button mashers send multiple requests to the page.

That being said if you want it absolutely bullet proof then disable the submit button on submission then process your page and do a redirect. If you dont redirect and the client refreshes the page the information is resubmitted with the form values and another email is generated.

Earl
www.jhdesigninc.com