The onchange event in Ajax

[SafetyWeek]

Hi everyone, I need your help.

I used the onchange event in select:

<select name="menu" 
onchange="window.location.href='?code='+this.options[this.selectedIndex].value;">
<option value="code1">Testo 1</option>

After loading I can read the value parameter code and show / hide items in relation to that value.

Now I upgraded to AJAX and I find this situation:

<select name="code" id="code" onChange="cerca_province();">
<option value="code1">Testo 1</option>

function cerca_province() 
{

code=document.form.code.options[document.form.code.selectedIndex].value

    if (window.XMLHttpRequest) {
        estrai_province= new XMLHttpRequest();
        estrai_province.onreadystatechange = ricevi_province;
        estrai_province.open("GET", "estrai.asp?code="+code, true);
        estrai_province.send(null);

    } else if (window.ActiveXObject) {
        estrai_province= new ActiveXObject("Microsoft.XMLHTTP");
        if (estrai_province) {
            estrai_province.onreadystatechange = ricevi_province;
            estrai_province.open("GET", "estrai.asp?code="+code, true);
            estrai_province.send();

        }
    }
}


  function ricevi_province() {   
    var province;       
	  if (estrai_province.readyState == 4) {	    
		  province=estrai_province.responseText;

			document.getElementById('provincia').innerHTML = province;
			 }
	}

But this way I can not read the value of parameter code and show / hide items in relation to that value.


Can you help me? Can someone help me?
Thanks in advance.

[SafetyWeek]

I try this but not working:

<select name="codice" id="codice" onChange="cerca_province(this.value);">
<option value="codice1">Testo 1</option>

[Dormilich]

to use cerca_province( this.value); you have to define a parameter in the function definition:

function cerca_province(val)
{ /* your function code */ }

PS. and of course you have to use the defined parameter.

PPS. with proper event handling, you could get the select’s value without further ado through this.value anywhere in the function.

[SafetyWeek]

Thanks for your suggestion, but not working...

In the asp page estrai.asp the value of parameter "codice" is correct but in the this asp page (index.asp) I don't not read the value of parameter "codice".

I don't receive error... but not read the value of parameter...

Can someone help me?

index.asp

<html>

<head>
<meta content="text/html; charset=utf-8" http-equiv="Content-Type" />
<script type="text/javascript" language="javascript">

var estrai_province;
var codice

function cerca_province(codice) 
{
    if (window.XMLHttpRequest)
    {
        estrai_province = new XMLHttpRequest();
    }
    else if (window.ActiveXObject)
    {
        estrai_province = new ActiveXObject("Microsoft.XMLHTTP");
    }
    
    if (estrai_province)
    {
        estrai_province.onreadystatechange = ricevi_province;
        estrai_province.open("GET", "estrai.asp?codice="+codice, true);
        estrai_province.send(null);
    }
}

  function ricevi_province() {   
    var province;       
	  if (estrai_province.readyState == 4) {	    
		  province=estrai_province.responseText;

			document.getElementById('provincia').innerHTML = province;
			 }
			 
	}
   
</script>
</head>


<body>
<form method="post" action="" name="form">
<table>

<%nome_form="form"%>

<tr>
<td>
<select name="codice" onChange="cerca_province(this.options[this.selectedIndex].value);">
<option value="0">Seleziona</option>
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
<option value="4">4</option>
</select>
</td>
</tr>
	
<tr>
<td id="provincia"></td>
</tr>

</table>   

//// This value not read ////    				
<% response.write request.querystring("codice") & "<br>" %>

</form>

</body>

</html>

[Dormilich]

Thanks for your suggestion, but not working...

not the way you think …

given the way AJAX works, why should line #68 return something at all?


one correction to make: remove var codice, codice is a parameter, not a variable.

[SafetyWeek]

OK, I correct the code.

Link of the page: http://www.romatitlan.com/public/index.asp

I need read the value of parameter "codice" also on the page index.asp.

It's possible?
Thanks.

[SafetyWeek]

you can do?

[Dormilich]

given your link, the AJAX works without fail.

[SafetyWeek]

Yes, I have modify the script and I read the value of codice in the index.asp

But if I use the codice_value in the server language, for example in ASP query:

SELECT * FROM tbl WHERE codice_value = ???

What value should I write in this query?

[Dormilich]

er, I didn’t understand that question.

[SafetyWeek]

I need execute ASP query using the value of variable "codice".

I read in the index.asp the value of variable "codice" with:

<span id="codice_value"></span>

how do I change this ASP query ? :

SELECT * FROM tbl WHERE codice_value = ???

Thanks for your attention.

[Dormilich]

sorry, but I can’t help you with ASP related questions.