无法使用PHP $ _POST数组检索输入字段值

I cannot get the $_POST['value'] after form submission.

I have used javascript to assign a value to an input field. code:

function updateValue(pid, value){
    // this gets called from the popup window and updates the field with a new value
    document.getElementById(pid).value = value;
}

The above function is called by a popup widow to assign a value to my input field: pid

Here is the form script:

<form action="test.php" method="post">
  <input type="text" name="project_name" id="pid" disabled="disabled" />
  <input type="submit" id="search" name="search" value="Search" />
</form>

In my test.php, I have done:

include 'functions.php'; //Has the connection script
if (isset($_POST['search'])){
    echo $project_id = $_POST['project_name'];
    $sql = mysql_query("SELECT * from item
                    where category like '$project_id %'
                    ");
    echo $num = mysql_num_rows($sql);   
}

But I am getting the error: Undefined index: project_name

Disabled inputs doesnt post. Use hidden input like this:

<form action="test.php" method="post">
  <input type="text" name="project" disabled="disabled" />
  <input type="hidden" name="project_name" id="pid" />
  <input type="submit" id="search" name="search" value="Search" />
</form>

your project_name input field is disabled. remove this attribute then it will work.

It's because disabled attributes aren't passed along the form requests.

If you're setting the value through javascript, and that part works, replace your text input with this:

<input type="hidden" name="project_name" id="pid" />

this will work

Try filling the hidden field when you set the value into disabled field

<form action="test.php" method="post">
      <input type="text" name="project" id="pid" onchange="document.getElementById("pid-new").value=document.getElementById("pid").value" disabled="disabled" />
      <input type="hidden"  id="pid-new" name="project_name" />
      <input type="submit" id="search" name="search" value="Search" />
    </form>