A form is a section of an HTML document where you put input controls (text boxes, check boxes, radio buttons, and pull-down lists)
Suppose you have 3 images in your image folder, and you want to display images dynamically by the users choice.
This is easily done by a little Razor code.
If you have an image called "Photo1.jpg" in your images folder on your web site, you can display the image using an HTML <img> element like this:
The example below shows how to display a selected picture which the user selects from a drop-down list:
The server creates a variable called imagePath.
The HTML page has a drop-down list (a <select> element) named Choice. It lets the user select a friendly name (like Photo 1), and passes a file name (like Photo1.jpg) when the page is submitted to the web server.
The Razor code reads the value of Choice by Request["Choice"]. If it has a value the code constructs a path to the image (images/Photo1.jpg, and stores it in the variable imagePath.
In the HTML page there is an <img> element to display the image. The src attribute is set to the value of the imagePath variable when the page displays.
The <img> element is in an if block to prevent trying to display an image with no name (like the first time the page is displayed.