无法在脚本函数中传递php变量

Question

i am creating two text areas with id's-id1$i(when,$i=1) and id1$i(when,$i=2)..what i want is that as soon as user changes the text of any of these text areas it should display that text in an alert box.Here is my code:

<?php
$i=1;
while($i)
    {
    echo '<textarea id="id1$i" onchange=Display("id1$i")></textarea>';
    echo "id1$i..<br>";
        if($i==2){break;}
     $i=2;
     }
?>
<input name="Submit" type="submit" value="Submit"/>
<script>
function Display(id1$i)
         {
             alert(document.getElementById("id1$i").value);
             }
</script>

Now when i try running this...the problem is when i enter "one" in the first text area box,it displays "one",that's ok.....but when i enter "two" in the second text area box,it still displays "one"...:mad::mad::mad:...

The only reason dat i can think of why it's hapning lyk dat is the function Display(id1$i) is not taking the value of $i=2...please help!!..

If i use proper names like "id11" and "id12"(i.e i dont use the variable $i anywhere in my code or say if i harcode everythng)..then the code works fine..it displays both "one" "two",respectively..

Answer 1

You can't embed PHP like that. You'll need to use the <?php ?> tags, therefore you'll need to change:

function Display(id1$i)
// ...
alert(document.getElementById("id1$i").value);

to:

function Display(id1<?php echo $i; ?>)
// ...
alert(document.getElementById("id1<?php echo $i; ?>").value);

And to use variables inside strings directly you can only use " therefore you can do one of the following:

'<textarea id="id1'. $i .'" onchange=Display("id1'. $i .'")></textarea>'
// or
"<textarea id=\"id1$i\" onchange=Display(\"id1$i\")></textarea>"