Please consider the following.This is what I have been trying to do. 1)I have a drop down list which can be used to select semesters. 2)Once I select the semester,courses for that semester should appear in another drop down list. 3)As the semester changes courses may also have to change.
My database
course_info(courseID varchar(15) primary key,courseName varchar(30),semester int)
This is what I did using ajax,php and mysql.
My html page
<html>
<head>
<script>
function showsemester(str) {
if (str=="") {
document.getElementById("txtHint").innerHTML="";
return;
}
if (window.XMLHttpRequest) {
// code for IE7+, Firefox, Chrome, Opera, Safari
xmlhttp=new XMLHttpRequest();
} else { // code for IE6, IE5
xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
}
xmlhttp.onreadystatechange=function() {
if (xmlhttp.readyState==4 && xmlhttp.status==200) {
document.getElementById("txtHint").innerHTML=xmlhttp.responseText;
}
}
xmlhttp.open("GET","showsemester.php?q="+str,true);
xmlhttp.send();
}
</script>
</head>
<body>
<form>
<select name="users" onchange="showsemester(this.value)">
<option value="">Select a semester:</option>
<option value="1">Y i S i</option>
<option value="2">Y i S ii</option>
</select>
</form>
<br>
<div id="txtHint"><b>courses will be listed here.</b></div>
</body>
My php page
<?php
$q = intval($_GET['q']);
$con = mysqli_connect('localhost','root','','scifac');
if (!$con) {
die('Could not connect: ' . mysqli_error($con));
}
$sql="SELECT * FROM course_info WHERE semester = '".$q."'";
$result = mysqli_query($con,$sql);
echo "<table border='1'><tr><th>course ID</th><th>name</th><th>semester</th></tr>";
while($row = mysqli_fetch_array($result)) {
echo "<tr>";
echo "<td>". $row['courseID'] . "</td>";
echo "<td>" . $row['courseName'] . "</td>";
echo "<td>" . $row['semester'] . "</td>";
echo "</tr>";
}
echo "</table>";
mysqli_close($con);
?>
Now it produces the result in a div as a table and working properly without any errors.But I would like to take the cours names as options in a drop down list and course ID as the values.
Your kind consideration given with this regard is highly appreciated. Thank you. T
