Check for blank Textboxes with PHP

f you remember the script that we wanted to create earlier it was this:

1. Get the text that a user entered in a textbox on a form
2. Trim any blank spaces from the left and right of the text
3. Check that what you have left is not a blank string

So we want to check that the textbox doesn't just contain this "". There has to be something in it, like "Bill Gates". Here's a script that does all three items on our list:

<?PHP

$user_text = trim("Bill Gates");

display_error_message($user_text);

function display_error_message($user_text) {

if ($user_text == "") {

print "Blank text box detected";

}
else {

print "Text OK";

}

}

?>

Try it out. When you run the script, you should find that Text OK prints. Now change this line:

$user_text = trim("Bill Gates");

to this:

$user_text = trim("");

Run your script again. This time, Blank text box detected should print out. Obviously, we're not getting the text from a textbox on a form, but just simulating the process. If you want to try out a version with all the HTML, here it is. This next script checks two textboxes on a form.