Syntax: checking if multiple variables are set

[lightnb]

Thank you! I didn't know there was a certain way to indent stuff (this is my first script), but now that I see it, it makes sense.

Is there a way to make Dreamweaver do the indenting for you?

I've added a bit more code to it, and I've got the new stuff running without errors, but It's not behaving as expected.

If I leave the "TD" input field blank, the code:

PHP Code:

if (isset($_POST['TD']) and !is_numeric($_POST['TD'])) 


Should evaluate false, and not generate a user error message. But it does...


If I give it all three values, this should check if they all add up corectly:

PHP Code:

if ( isset($HD) and isset($VD) and isset($TD) ) 
        {if ( $TD !== sqrt(($VD*$VD)+($HD*$HD)) )
            {$error_str .= "<li>We're sorry, but you can't change the laws of physics!</li>";
            }
        } 


But it says they're wrong even when I use 3,4, and 5, which should evaluate corectly.



And finally, this:

PHP Code:

if ( isset($HD) and isset($VD) and !isset($TD) ) 
        
        {$TD=sqrt(($VD*$VD)+($HD*$HD));
        echo $TD;
        } 


should take the first two input numbers, do the math, and spit out the answer (preferably back in the third input field), but it only gives me a blank page (when I comment out the other sections, so that I can get that far).


Here's the whole thing in context:

PHP Code:

<?php

// function to output form and hold previously entered values.

function user_form()
{
    //output the form HTML.
    echo '<p>Please fill in at least two fields.</p>';
    echo '<form action="'.htmlspecialchars($_SERVER['PHP_SELF']).'" method="post">';
    echo '<table border="0" cellspacing="4" cellpadding="0">';
    echo '<tr><td>Vertical Distance:</td><td><input type="text" name="VD" value="'.htmlspecialchars($_POST['VD']).'"></td></tr>';
    echo '<tr><td>Horizontal Distance:</td><td><input type="text" name="HD" value="'.htmlspecialchars($_POST['HD']).'"></td></tr>';
    echo '<tr><td>Throw Distance:</td><td><input type="text" name="TD" value="'.htmlspecialchars($_POST['TD']).'"></td></tr>';
    echo '<tr><td colspan="2"><input type="submit" value="Add to Database" name="submit"></td></tr>';
    echo '</table>';
    echo '</form>';

}

// has the form been submitted?
if (isset($_POST['submit']))
{
    // the form has been submitted
    // perform data checks.

   $error_str = ''; // initialise $error_str as empty

    if (isset($_POST['VD']) and !is_numeric($_POST['VD']))
    {
        $error_str .= '<li>VD must be a number</li>';
    }
    if (isset($_POST['HD']) and !is_numeric($_POST['HD']))
    {
        $error_str .= '<li>HD must be a number</li>';
    }
    if (isset($_POST['TD']) and !is_numeric($_POST['TD']))
    {
      $error_str .= '<li>TD must be a number</li>';
    }

    // now, have any of these errors happened? We can find out by checking if $error_str is empty
    if (!empty($error_str))
    {
        // errors have occured, halt execution and show form again.
        echo '<p>There were errors in the information you entered, they are listed below:</p>';
        echo '<ul>'.$error_str.'</ul>';

        // show form again
        user_form();

        exit; // die
    }
    else
    //Here is where we put all the stuff we want it to do!
        
    {
        $error_str = '';    //Reset the error store
           
        if ( isset($HD) and isset($VD) and isset($TD) ) 
        {if ( $TD !== sqrt(($VD*$VD)+($HD*$HD)) )
            {$error_str .= "<li>We're sorry, but you can't change the laws of physics!</li>";
            }
        }
        
        
        
        if ( isset($HD) and isset($VD) and !isset($TD) ) 
        
        {$TD=sqrt(($VD*$VD)+($HD*$HD));
        echo $TD;
        }
    
    
    
        if (!empty($error_str))
        {
        // errors have occured, halt execution and show form again.
        echo '<p>There were errors in the information you entered, they are listed below:</p>';
        echo '<ul>'.$error_str.'</ul>';

        // show form again
        user_form();

        exit; // die
           }
    
    
    
    }
    
    
    
    
    // if we get here, all data checks were okay, process information as you wish.
}
else
{
    // the form has not been submitted, let's show it
    user_form();
}


?>

I tried to do the indenting thing with all the brackets.

This is my first time doing this, and I appreciate your taking the time to help me.