Question

I want to reload my page (PHP) on changing value from the dropdownmenu and passing the value of selected item as a variable alongwith one another variable to the page. I have tried following –

<select name="application" onChange=Refresh(this.value,$query)" \>
<option>Any Application</option>
<option>ChIP</option>
<option>Enzyme Immunoassay</option>
<option>ELISA</option>
<option>Flow Cytometry</option>
<option>FACS</option>
</select>

The Refresh function is:

function Refresh(id,gene){
location.href="getnet.php?app=" + id + "&query=" + gene;
}

And i am receiving variables as:

$query = $_POST['gene'];
$app = $_POST['application'];

Answer 1

you must use form submit() method in onchange event of the dropdown and hidden field for second parameter, for example:

<form name="myForm" method="GET" action="<?php echo $_SERVER['PHP_SELF'];?>">
  <select name="first" onChange="document.myForm.submit();">
    <option value="1">Value 1
    <option value="2">Value 2
    <option value="3">Value 3
  </select>
  <input type="hidden" name="second" value="second parameter value"/>
</form>

On the server side you can get your variables in $_GET supperglobal array like:
$_GET['first'] – it’s value from dropdown element and $_GET['second'] – second hidden param.