do i need eval() function here?

[ATS16805]

(text revised)

hello all. please take a look at my code. this is just a snippet of something, but the part i'm concerned with is the FOREACH loop, and the html i'm outputting-- trying to test why the session variable in the IF expression is NOT evaluating as the actual session-variable value, but instead-- (i think) its acting as if its a string?

notice that i've created a little html echo before during and after the FOREACH so i can see what's going on. the resulting screen html output shows the values as they appear in the array, only if i remove the $_SESSION[] bit, and leave $varloop (which of course, should replace $tempy, as also did the original session var before i tried the eval() thing)

i really have no idea what's happening... so looking for those of you w/ experience. thanks!

edit: out of forum-practice here-- i should explain that the whole point is i'm trying to evaluate whether a form entry is valid or not by looping through an array, and putting the form field values into session like that.
is this breaking because it's a bad idea, or bad execution of an otherwise functional idea?

<!-- heredoc2 end --></div> 
EODREP;

$htmlvisible = $htmlreport;
$tempecho = "<div class=\"formtable\"><p class=\"errortrip\">";
$js = "<ul>";	
// must validate form and show results
$formvariables = array('las_name','fir_name','age','email','phone','street_addr','city','zip');
foreach($formvariables as $varloop) {

if ($_SESSION['$varloop'] = '') {
	$tempecho .= "Your entry was rejected because you MUST submit info for each required field!</p><p>We're sorry to ask you to <a href=\"schedule.php\">submit another form</a>, but our server has rejected your entry. Please try again.</p><p>Thank you for your understanding.</p>  <!-- end of general-error -->  </div>";
} else $tempecho = $tempecho;

/*  test why the session variable evaluated by the IF logic is NOT giving me what i expect (i'm expecting the $formvariables array value) */
	/* $tempy = eval(echo $_SESSION[$varloop];); */

$js .= "<li>before it and ".$tempy." after the dynmic data </li>";

}
$js .= "</ul>";
echo $js;

[cdwhalley_com]

This bit:

if ($_SESSION['$varloop'] = '') {

should be:

if ($_SESSION[$varloop] = '') {

if you're trying to do what I think you're trying to do...

[ATS16805]

say in reverse i my words...
yeah, i'm educated!

i've done a horrid job of explaining my intended purpose here.
a few things to consider (in case the var names didn't make it obvious):

the script is prepping data for entry into a 'customers db'.
the data is entered via html form, posting to itself method
trying to validate the data before it hits the sql query
this bit i've pasted, the first flow control expression, is meant to catch any empty data submitted / empty fields
the $formvariables array holds the names of the FORM post data
FOREACH puts array vals of $formvariables into $SESSION vars to test the session vars against the IF Expression (tried $POST in place of $_SESSION: no recognizeable difference)

output skips this IF case even if blank form is submitted
obvious error in script.

oh, and removing the single quotes also causes no difference in flow / intended outcome that i can see. i actually tried that as one of my first debugging attempts hours ago, but tried again for good measure. still nothing, but thanks for your input cdwhalley.