javascript to check the text of a textbox and then continue

[buran]

Dear ASP.NET Programmers,

I have a question about a script I'm trying to code and invoke when a button
(btnSave) is pressed on the page. This script should only run when a textbox
(txtAD) on the page is left blank. I tried to use a code snippet with the
"return confirm" function but without success. The code should check whether
the textbox is empty or not, and if empty, it should ask the user to
continue and then run the next code. How can I accomplish this? Thanks in
advance,

Buran

 

[JustinBlat]

Buran,
you're going to want to capture the client onclick event of your save
button, and run the script from there. First, in your codebehind
append the client event handler:

btnSave.Attributes.Add("OnClick","return CheckForEmptyTextbox();");

Now the javascript function CheckForEmptyTextbox will be called when
the button is clicked. This function needs to return a boolean value,
telling the page whether or not to submit the form.

<script language="JavaScript">
function CheckForEmptyTextbox() {
var continue;
var txtAD;

// first get a reference to the textbox object
txtAd = document.getElementById('txtAD');

// check if the textbox is blank
if (txtAD.value == '') {

// since the textbox is blank, ask the user if they want to
continue
continue = confirm('txtAD is blank, do you want to continue?');

return continue;

} // end if

// since the value is filled in, just return true
return true;

} // end function
</script>

 

[buran]

Dear JustinBlat,

I tried your code, but unfortunately I could not manage it to work.

In my code-behind:

Private Sub Page_Load(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles MyBase.Load
btnSave.Attributes.Add("OnClick", "return
CheckForEmptyAdmissionDate();")
LoadControls()
If Not Page.IsPostBack Then
LoadData()
End If
End Sub

Then, in my aspx page:

<script language="JavaScript">
function CheckForEmptyAdmissionDate() {
var continue;
var txtAD;
txtAD = document.getElementById('txtAD');
if (txtAD.value == '') {
continue = confirm('Admission Date is blank, do you want to
continue?');
return continue;
}
return true;
}
</script>

When I press the button (btnSave), the page is submitted although the txtAD
textbox is empty. What may cause this problem?
Thanks in advance,

Buran