In this example, i?m triying to recover an indeterminate number of vars from a form with the code below. The type of vars is like this: $var1, $var2, $var3, ... but the succesion can be incomplete like this $var1, $var5, $var6, ...

for ($n=0; n<=10; $n++) {
   if (isset(eval("\$var".$n.";")) {
      [...]
   }
}

and the error message is:
Parse error: parse error, unexpected T_EVAL, expecting T_VARIABLE or '$' in d:\inetpub\wwwroot\administracion\val_empextdb.php on line 14

Thanks.