[Resolved] function not adding previous result

[ajberry]

I have the following code that lists a product and gives a quantity box which the user can input quantities and upon adding to cart it refreshes the page with the quantity inputted plus any quantity that was already in there. This works inline, but when put into a function it does not keep a running total of the quantity, it just outputs the last quantity entered.

session_start();
@ $Item1 = $_POST['Item1'];

function addTo($var)
	{
		if (!empty($var))
			{
				@ $_SESSION[$var] += $var;
			}
	}

function inCart($var)
{

	if (!empty($_SESSION[$var]))
		{
			echo "<strong>" . $_SESSION[$var] . "</strong>";
		}
	else
		{
			echo "0";
		}
}

// First Item	
		echo "<form action=\"" . $_SERVER['PHP_SELF'] . "\" method=\"post\">
			  <table align=\"center\" width=\"40%\">
			  <thead>
			  <tr>
			    <th>In Cart</th><th align=\"left\">Product</th><th>Unit Price</th><th>&nbsp;</th>
			  </tr>
			  <tr>
				<td align=\"center\">";
		addTo($Item1);
		inCart($Item1);

echo "  </td><td>IBM A20m Laptop</td><td align=\"center\"><b>$395.00</b></td><td>&nbsp;</td>
			  </tr>
			  <tr>
			  	<td colspan=\"4\" align=\"right\">Quantity:&nbsp;&nbsp;<input name=\"Item1\" type=\"text\" size=\"5\" maxlength=\"5\"></td>
			  </tr>
			  <tr>
			  	<td colspan=\"4\" align=\"right\"><input type=\"submit\" name=\"S1\" value=\"Add to Cart\"></td>
			  </tr>
			  </table>
			 ";

	echo "</form>";

Inline Working PHP Code:

if (!empty($Item1))
			{
				@ $_SESSION['Item1'] += $Item1;
			}
		if (!empty($_SESSION['Item1']))
			{
				echo "<strong>" . $_SESSION['Item1'] . "</strong>";
			}
		else
			{
				echo "0";
			}

[Weedpacket]

$_SESSION[$var] += $var;

You mean if $var==5, this should evaluate to $_SESSION[5] += 5; if not, what should it evaluate to?

I think you're wanting to pass the name of the variable (as a string) to the function, not the value.

function addTo($var)
{
    if (!empty($$var))
    {
        @ $_SESSION[$var] += $$var;
    }
}
.....
$Item1 = 5;
addTo('Item1');

But that won't work, because if you call addTo('Item1'), then the function becomes "if (!empty($Item1)){@ $_SESSION['Item1'] += $Item1;}", and $Item1 doesn't have a value.

function addTo($name, $value)
{
    if (!empty($name))
    {
        @ $_SESSION[$name] += $value;
    }
}
...
addTo('Item1', 5);