Possible to execute a dynamic condition?

Hi,
is it possible to execute a condition that is dynamic?
For example:

$from = "John";
$field1 = "from";

$str = '$'.$field1.' == " '.$from.' " ';
if ($str) {
print "HI";
}

I would want it to execute:
if ($from == "John") {
print "HI";
}

I have tried it out but it doesn't work. The statement is always true. I have tried changing "==" to "!=".

I think you're going to need to use evail on your $str variable.

The concept is called "variable variables". The reference is http://www.php.net/variables.variable

I've not done this a great deal myself, but I think that

$from = "John";
$$field1 = "from";

if ($field1 == $from) {
print "HI";
}

is pretty close to the solution.

HTH,

[edit]had it a tad brain dead... fixed...[/edit]