Conditional links in html

Not sure about HTML but you could certainly do it using PHP and Ajax. The PHP script would just be a self submitting form and would submit into the url. For instance;

$link = "FORM HERE";

Then you would %_GET the form and the URL would be something like this;

echo "<a href='http://webmastertalk.com/images/$link.jpg'>Image:$link</a>";

The examples above a very rough but you get the idea.

Do a bit of research into PHP and Ajax and you'll be there in no time!

HTML doesn't do things like that, to my knowledge. It's a markup language, not a programming language. HTML5 changes that a bit, but that's really because of the tighter integration of javascript.

You could use javascript to evaluate the results of an html FORM data field, but it would still be JS doing the conditional logic.

JavaScript that baby.

var a = document.getElementById("linkid");    
a.href = "http://hewlink.com";

Where linkid is the ID of your hyperlink <a> tag.