This is probably very simple, but it is driving me crazy!
I create the variable to be used in the header statement containing page and variable to be passed, based on a couple of PHP variables
if ($var === "A"){
  $backto = "page1.php?va=".$rbooktype; 
} else if ($var === "B"){
  $backto = "page2.php?va=".$rbooktype; 
}  else {
  $backto = "page3.php?va=".$rbooktype; 
}
($rbooktype is declared earlier in the script)
My question is how to use the $backto variable in a header(location:…) statement?
Many thanks