Html append text value to form action

htmlwebforms

I have a form, text input and a submit button. How do I append the value of the text box to the form action i.e.

action="https://www.mywebsite.com/" & txtSessionId

The form looks like this:

<form name="form1" method="post" action="https://www.mywebsite.com/">
  <label>Your Sessions ID:
    <input type="text" name="txtSessionId" id="txtSessionId">
  </label>
  <label>
<input type="submit" name="btnContinue" id="btnContinue" value="Continue">
</label>
</form>

I want the link to look like this: https://www.mywebsite.com/123456

where 123456 is typed into the text box by the user.

Thank you

Best Solution

You'd have to either use javascript or something server-side to do that (or both).

Javascript:

<form name="form1" method="post" action="https://www.mywebsite.com/" 
  onsubmit="location.href = this.action + this.txtSessionId.value; return false;">

Server-side (PHP)

if (!empty($_POST['txtSessionId']))
{
    header('Location: https://.....' . (int)$_POST['txtSessionId']);
    exit();
}