The primary tag used in HTML forms is the <input /> tag. The input tag prompts your readers to input data to your Web server.
There are ten specific types of <input /> tag:
You choose which type of input tag you would like by placing it in the type="" attribute of the tag. For example:
<input type="text" />
Button
<input type="button" value="button" name="button" />The button input type allows you to create custom input buttons that do not have the default effects of the submit and reset buttons. It is most commonly used with JavaScript forms with the onClick attribute so that data is not sent to the Web server until the JavaScript has processed it. This field is blank by default. If you want it to say something, use the VALUE="" attribute.
Checkbox
<input type="checkbox" /<With a checkbox element, you can give your readers a list of items to choose from. They can choose more than one in the list. Or it can be used as a "yes/no" toggle, when there is only one option. If you have a group of checkboxes, link them all together by giving them the same name. The values will all be sent to the form separately.
File
<input type="file" />The file input type allows your readers to upload a file to your Web server. If you read my article on CGIs and File Upload, you can learn more about how to use the file input type.
Hidden
<input type="hidden" />Hidden fields are used to "save state" within an HTML form. They are most often used in forms that have multiple pages and information that needs to be carried from one page to the next. They are not shown on the Web page, but the information is sent along with other form input fields.
Image
<input type="image" src="ABCbuttn.gif" width="88" height="31" alt="About.com - image courtesy About.com" border="0" />With the image input type, you have yet another option for a button on your forms. The image shown here happens to look like a button, but you can use any image as a button on your forms. One thing to note, images as submit buttons don't allow for the tab key to move the focus to it, and this makes them less accessible for people with no mouse.
Password
<input type="password" />The password field looks almost identical to the text field. However, when you type in it, the letters are hidden. This allows you to have a little more security for passwords on your forms. Remember, however, that the passwords are not sent encrypted in any way. So don't rely on this to secure truly important secret information.
Radio
<input type="radio" />Radio buttons give readers a "one of many" choice combination. Like the checkbox input type, radio button groupings all have the same NAME, and each value is different. If a reader chooses one value, all the other values will be deselected.
