Hi,

I've been trying to get this code working, but it doesn't ;-) I searched for information on the get method and used the w3 validator to find the problem. The sql syntax does show the wanted value (when I fill in the variables), so I think it's in the combination of files. Since I think it's in the .js file, I post here for help.

What it should do is this:
1. after selecting an option in the dropdown, it does get the column names of the table from the dbase. so far, so good.
2. I want it to get the highest number in a certain column (fyi; the unique number in this case) , for example 9,
3. and show the number 10 as a value in the textbox.

It might/should be possible to do it all at the same time, which I also want to understand/learn, but the one after the other would be quite a learning point as well.

Any help is highly appreciated.

this is the code:
HTML Code:
<html>
<script src="gettablelist.js"></script>
<script src="getrecordvalue.js"></script>

<body>

<form action="insert.php" method="post">
Table name: <?php include ('tabledroplist.php') ?><br>
Waarde 1: <input type="text" id="row1" name="row1" value="-" onChange="showRecordValue(this.value)"><input type="text" name="value1" value="."/><br>
Waarde 2: <input type="text" id="row2" name="row2" value="-" ><input type="text" name="value2" /><br>
Waarde 3: <input type="text" id="row3" name="row3" value="-" ><input type="text" name="value3" /><br>
Waarde 4: <input type="text" id="row4" name="row3" value="-" ><input type="text" name="value3" /><br>
Waarde 5: <input type="text" id="row5" name="row3" value="-" ><input type="text" name="value3" /><br>
Waarde 6: <input type="text" id="row6" name="row3" value="-" ><input type="text" name="value3" /><br>
Waarde 7: <input type="text" id="row7" name="row3" value="-" ><input type="text" name="value3" /><br>
Waarde 8: <input type="text" id="row8" name="row3" value="-" ><input type="text" name="value3" /><br>
Waarde 9: <input type="text" id="row9" name="row3" value="-" ><input type="text" name="value3" /><br>
Waarde 10: <input type="text" id="row10" name="row3" value="-" ><input type="text" name="value3" /><br>
Waarde 11: <input type="text" id="row11" name="row3" value="-" ><input type="text" name="value3" /><br>
<input type="submit" />
</form>
</body>
</html>
getrecordvalue.js:
Code:
function showRecordValue(str)
{
	var column = str;
	var table = document.getElementById('users').value;
	var xmlhttp = new XMLHttpRequest();
	xmlhttp.onreadystatechange = function()
	{
		if (xmlhttp.readyState==4 && xmlhttp.status==200)
		{
		var response = xmlhttp.responseText + 1;
		document.getElementByName('value1').value=response;
		}
	};
	xmlhttp.open('GET', 'find_highest_value.php?column=' + str +'&table=' + table, true);
	xmlhttp.send();
}
find_highest_value.php:
PHP Code:
<?php
$column
=$_GET["column"];
$table=$_GET["table"];

//create connection with db
include('db_connect.php');

//build query
$query "SELECT MAX(".$column.") AS ".$column."FROM ".$table
$result mysql_query($query) or die(mysql_error());

// store the record of the "example" table into $row
$row mysql_fetch_array$result );

// Print out the contents of the entry 
echo $row;

mysql_close($con);
?>