date drop down list validation

[son]

hi have have 3 drop down lists one for day one for month and one for year... i would like to add validation to the user so that if for example they select from the drop down list the date 31st february it will tell them that it is an invalid date...

 

anyone have any suggestions for me.. thanks in advance sonia...

[wessamzeidan]

You have to use a client script to do that.

 

You can do it another way, when the user selects a month, fill the days ddl dynamicaly, this way the user won't be able to do a wrong selection, but it would require an additional postback to the server...

[son]

hi i am trying to do it this way but it keeps on giving me errors that i have my input string in an incorrect format... can some one please help... getting really frustrated me been on it all day..

 

my code for the drop down lists is as follows

 

 Private Sub ddlMonth_SelectedIndexChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles ddlMonth.Init

       Dim i As Integer
       For i = 1 To 12
           ddlMonth.Items.Add(MonthName(i).ToString)
       Next
       ddlMonth.SelectedIndex = Date.Now.Month - 1
   End Sub


   Private Sub ddlYear_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles ddlYear.Init

       Dim i As Integer
       For i = Date.Now.Year - 5 To Date.Now.Year + 5
           ddlYear.Items.Add(i)
       Next
       ddlYear.SelectedIndex = Date.Now.Year - (Date.Now.Year - 5)
   End Sub

 

the code i have to save the changes is as follows

 

Private Sub btnSave_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSave.Click


       Dim a1 As Integer = ddlMonth.SelectedIndex
       If ddlDay.SelectedValue = "31" Then
           If a1 = 1 Or a1 = 3 Or a1 = 5 Or a1 = 8 Or a1 = 10 Then
               Response.Write("<script>alert('Invalid Date')</script>")
           End If
       End If

              Dim mydate As String

       mydate = ddlDay.SelectedItem.Text + "/" + ddlMonth.SelectedItem.Text + "/" + ddlYear.SelectedItem.Text
       Dim a As DateTime = mydate


       Dim SqlSPParam2 As String = "@news_TitleEN"
       Dim SqlSPParam3 As String = "@news_TextEN"
       Dim SqlSPParam8 As String = "@news_dt"

       Dim SqlParams As SqlParameter() = {New SqlParameter(SqlSPParam3, TextBox3.Text), New SqlParameter(SqlSPParam3, TextBox2.Text), New SqlParameter(SqlSPParam8, a)}
       WfSqlDataPump.ExecuteNonQuery(connectionString, "sp_addnews", SqlParams)

       lblMessage.Text = "The News has been saved!"
         

   End Sub

 

when i am debbugging the code it gets stuck where i have the a variable which is declared as a string and tells me that i have the input string in invalid format.....

 

thanks in advance sonia.. ;)

[sj1187534]

Can you please tell exactly where you are getting the error? I didn't understand what you are pointing at.

 

Or maybe you can try this:

 

...

 

Dim a as DateTime = cDate(mydate)

 

...

 

SJ

[son]

hi thanks for ur reply i did try what u recommended but i still keep on getting the error - Cast from string "31/6/2004" to type 'Date' is not valid.

 

i keep on getting the error cause since i am putting the values that i have in the three dropdownlists into a string and then passing it to datetime variable it brings this error that i have mentioned above.

 

the error is cropping up in the code below where i have the "a" declared as datetime. its not accepting the string of "mydate" variable to be put into the textbox

 

 Dim a1 As Integer = ddlMonth.SelectedIndex
       If ddlDay.SelectedValue = "31" Then
           If a1 = 1 Or a1 = 3 Or a1 = 5 Or a1 = 8 Or a1 = 10 Then
               Response.Write("<script>alert('Invalid Date')</script>")
           End If
       End If

              Dim mydate As String

       mydate = ddlDay.SelectedItem.Text + "/" + ddlMonth.SelectedItem.Text + "/" + ddlYear.SelectedItem.Text

       Dim a As DateTime = mydate

textbox1.text = a

do u know how i can go around this.. thanks in advance..;)

Edited May 3, 2004 by son

[sj1187534]

Hi..

 

I have a few questions on your code. Can you paste the exact error?

 

One of the questions is the usage of '+' for string concatenation. I think you need to use '&' for that.

 

SJ

 

 

hi thanks for ur reply i did try what u recommended but i still keep on getting the error - Cast from string "31/6/2004" to type 'Date' is not valid.

 

i keep on getting the error cause since i am putting the values that i have in the three dropdownlists into a string and then passing it to datetime variable it brings this error that i have mentioned above.

 

the error is cropping up in the code below where i have the "a" declared as datetime. its not accepting the string of "mydate" variable to be put into the textbox

 

 Dim a1 As Integer = ddlMonth.SelectedIndex
       If ddlDay.SelectedValue = "31" Then
           If a1 = 1 Or a1 = 3 Or a1 = 5 Or a1 = 8 Or a1 = 10 Then
               Response.Write("<script>alert('Invalid Date')</script>")
           End If
       End If

              Dim mydate As String

       mydate = ddlDay.SelectedItem.Text + "/" + ddlMonth.SelectedItem.Text + "/" + ddlYear.SelectedItem.Text

       Dim a As DateTime = mydate

textbox1.text = a

do u know how i can go around this.. thanks in advance..;)