Concatenating a variable and some input text.

gistfile1.html

<input type="text" name="message">
 
<button type="button" class="show-message">Show The Message...</button>
 
<script src="http://ajax.googleapis.com/ajax/libs/jquery/2.1.0/jquery.min.js"></script>
<script type="text/javascript">
    // wait for someone to click on a button
    $(".show-message").click(function() {
        // get the value of the input, and show it in a dialog
        // preface it with another string of text
        var greeting = "A message for you:";
        alert( greeting + $("input[name='message'").val() );
    });  
</script>