Pass variable from form to php - php

Question

Did my best to not post this question but i just can not figure this one out. I'm trying to pass a variable from my html form to a php script the code looks like this so far
<?PHP
echo "<b>Previously Submitted</b><br />";
echo "<select name='files' onChange='updateInfo();'>";
echo "<option value=''></option>";
$files = scandir("businesses");
foreach ($files as $file)
if($file != "."){
if($file != ".."){
if($file != "form.php"){
echo "<option value='$file'>". htmlspecialchars($file) ."</option>";
}
}
}
echo "</select>";
?>
<script type="text/javascript">
function updateInfo(){
<?PHP
mysql_connect("HOSTHERE","USERNAME","PASSWORD");
mysql_select_db("USERNAME");
//This is the line that is of interest i can't figure how to pass document.forms['frm'].files.value to my query
$bizname = mysql_query("SELECT `Value` FROM `" . document.forms['frm'].files.value . "` WHERE `Variable` LIKE 'Name'");
$bizValue = mysql_fetch_assoc($bizname);
echo "document.forms['frm'].businessname.value = '" . $bizValue['Value'] . "';";
mysql_close();
?>
}
</script>
Any help would be greatly appreciated on how i can pass a value from my drop down to the php code.
EDIT
Just to clear things up on what i'm doing sorry about some confusion basically i have a dropdown menu and when the dropdown menu is changed i want to query my database using whatever is in the dropdown as the table in the query and then what ever the value i get from the database is set in my form in a text field. It's all in one page and just trying to update the text filed when the dropdown is changed

Answer 1

The way you have written updateInfo script is not possible. using php concatenation (i.e ".") you can concatenate only php variables not java-script. PHP does not understand it.
what i suggest you is to use ajax. In your updateInfo pass the changed value.
<?php
echo "<select name='files' onChange='updateInfo(this.value);'>";
echo "<option value=''></option>";
$files = scandir("business");
foreach ($files as $file)
if($file != "."){
if($file != ".."){
if($file != "form.php"){
echo "<option value='$file'>". htmlspecialchars($file) ."</option>";
}
}
}
echo "</select>";
?>
and then send ajax and get response. and treat response as you want
<script type="text/javascript">
function updateInfo(val){
$.ajax({
url: '/path/to/ajaxrequest.php',
type: 'post',
data: {'file':val}
success: function(response){
document.forms['frm'].businessname.value = response;
}
});
</script>
and your ajaxrequest.php
<?php
if(!empty($_SERVER['HTTP_X_REQUESTED_WITH']) && strtolower($_SERVER['HTTP_X_REQUESTED_WITH'])=='xmlhttprequest'){
mysql_connect("HOSTHERE","USERNAME","PASSWORD");
mysql_select_db("USERNAME");
$file = mysql_real_escape_string($_POST['file']);
$bizname = mysql_query("SELECT `Value` FROM ".$file." WHERE `Variable` LIKE 'Name'");
$bizValue = mysql_fetch_assoc($bizname);
$assignVal = $bizValue['Value'];
mysql_close();
echo $assignVal;
}
?>
if you don't get this let me know. thank you.
here i am giving you a link to download code

Answer 2

Put tag inside the HTML Form element..Also I have not understood why you are merging javascript and PHP mysql update function.
yo can write code like
1.Form Element with
Done.

Answer 3

you need to submit the form. you can use post or get as method. but without submitting you can not pass variable from html to php.
<?PHP
echo "<form name='frm_1' id='frm_1' action='your_destination_page.php' method='post>'";
echo "<b>Previously Submitted</b><br />";
echo "<select name='files' onChange='updateInfo();'>";
echo "<option value=''></option>";
$files = scandir("businesses");
foreach ($files as $file)
if($file != "."){
if($file != ".."){
if($file != "form.php"){
echo "<option value='$file'>". htmlspecialchars($file) ."</option>";
}
}
}
echo "</select></form>";
?>
on destination page write this on the top of the page
<?php echo "<pre>";print_r($_POST);echo "</pre>";?>
you will have values of all controls in $_POST array.

Answer 4

<?PHP
echo "<b>Previously Submitted</b><br />";
echo "<select name='files' onChange='updateInfo();'>";
echo "<option value=''></option>";
$files = scandir("businesses");
foreach ($files as $file)
if($file != "."){
if($file != ".."){
if($file != "form.php"){
echo "<option value='$file'>". htmlspecialchars($file) ."</option>";
}
}
}
echo "</select>";
?>
<script type="text/javascript">
function updateInfo(){
<?PHP
mysql_connect("HOSTHERE","USERNAME","PASSWORD");
mysql_select_db("USERNAME");
//This is the line that is of interest i can't figure how to pass document.forms['frm'].files.value to my query
$bizname = mysql_query("SELECT `Value` FROM `" . document.forms['frm'].files.value . "` WHERE `Variable` LIKE 'Name'");
$bizValue = mysql_fetch_assoc($bizname);
$assignVal = $bizValue['Value'];
echo "<script>document.forms['frm'].businessname.value = '" .$assignVal . "';</script>";
mysql_close();
?>
}
Try enclosing in a script tag.