Usually that data is passed to a server side script which would process it, maybe store it in a database or file and then display the new page. Then every time that event needs to be displayed, it's recalled from wherever it was stored.
Javascript is not a server side language though. Javascript runs on the machine of the client, or the person using your website. Through javascript you won't be able to save the data. You can however manipulate the current page to show the event. Any changes would be lost when the page is refreshed. It's also possible to access the data on another page that the form sends you to.
Traditionally, when you submit a form the data is sent through a whole new request to the server. It can be to the same file or a different one. This data is then accessible to the script on the server side. Sense you are not using a server side language, one way is to make the form request a 'GET' request. This will include the data encoded into the URL. Then, through javascript, it's possible to dissect the url in order to retrieve the sent information.
Honestly, this is likely out of your ability if you've never worked with javascript before. If you have any specific questions, I can help you out. In the meantime... here's some related pointers:
- Adding an 'onclick' event listener onto the 'submit' input element will let you execute code before the new request is made. By having the event listener return false, it will prevent the default action (submitting the page) in some browsers. More complex solutions are needed for wider browser support.
- After a 'GET' request is complete, you can access the information through the url in javascript. One way might be to use the document.URL or document.location.href properties. Regular expressions might be useful here too.
- You can get an input field's current value by using the value property. For example, here is a valid javascript line that sets the value of the input textbox with the "id" property (... id="input_date" ...) of 'input_date' into the variable date: var date = document.getElementById("input_date").value;