将 PHP 变量传递到 Javascript window.location

我试图将 php 变量传递到 java 脚本 window.location 中，该脚本在从数据库中删除项目后将用户返回到当前列表视图。我似乎无法得到正确的语法。

Code:

function confirmation(a) {
var currString = "<? echo $currString ?>";
var answer = confirm("Are you sure you want to delete this item?")
if (answer){
    alert("The item has been deleted")
    window.location = "list.php?s='. $currString .'&=delete=true&id=" + a;
}
else{
    alert("The item has not been deleted")
}

尝试这个：

function confirmation(a) {
    var currString = "<?php echo $currString ?>";
    var answer = confirm("Are you sure you want to delete this item?");
    if (answer){
        alert("The item has been deleted")
        window.location = "list.php?s=" + currString + "&=delete=true&id=" + a;
    }
    else{
        alert("The item has not been deleted");
}