ถ้าต้องการให้ textbox ใส่แค่ตัวอักษรได้เท่านั้น ถ้ากดเป็นตัวเลขให้แสดง เมสเสสเตือน

    <script type="text/javascript">
        function isCharKey(evt) {
            var charCode = (evt.which) ? evt.which : event.keyCode
            if (charCode > 32 && (charCode < 48 || charCode > 57))
                return true;
            return false;
        }
    </script>

//<input type="text" onkeypress="return changeToUpperCase(event,this)" />

function changeToUpperCase(event,obj) {
    charValue = (document.all) ? event.keyCode : event.which;
    if (charValue!="8" && charValue!="0" && charValue != "27"){
        obj.value += String.fromCharCode(charValue).toUpperCase();
        return false;
    }else{
        return true;
    }
}

function integerOnly() {
    var keyCode = event.keyCode;
    return (keyCode >= 48 && keyCode <= 57);
}

function numberOnly(obj) {
    //if (window.event.keyCode) {
        var keyCode = event.keyCode;
        if (obj.value.indexOf('.') != -1 && keyCode == 46) {
            return false;
        }
        if (obj.value.indexOf('-') != -1 && keyCode == 45) { 
            return false;
        }
        if (obj.value.indexOf('+') != -1 && keyCode == 43) { 
            return false;
        }
        if (keyCode >= 48 && keyCode <= 57 || keyCode == 8 || keyCode == 46 || keyCode == 16 || keyCode == 9 || keyCode == 37 || keyCode == 43 || keyCode == 45) {
            return true;
        }
        return false;
    //}
}

function formatCurrency(num, ndec) {
    num = num.toString().replace(/\$|\,/g, '');
    if (isNaN(num))
        num = "0";
    if (isNaN(ndec))
        ndec = "0";
    sign = (num == (num = Math.abs(num)));
    num = Math.floor(num * 1000000 + 0.50000000001);
    cents = num % 1000000;
    num = Math.floor(num / 1000000).toString();
    if (cents < 10) cents = "00000" + cents
    else
        if (cents < 100) cents = "0000" + cents
        else
            if (cents < 1000) cents = "000" + cents
            else
                if (cents < 10000) cents = "00" + cents
                else
                    if (cents < 100000) cents = "0" + cents;
    for (var i = 0; i < Math.floor((num.length - (1 + i)) / 3); i++)
        num = num.substring(0, num.length - (4 * i + 3)) + ',' +
        num.substring(num.length - (4 * i + 3));
    num1 = cents + "00000";
    numx = num1.substring(0, ndec);
    if (ndec > 0)
        resultn = num + '.' + numx
    else resultn = num;
    return (((sign) ? '' : '-') + resultn);
}

sample : format(4567354.677623); // 4,567,354.68
*/
function formatCurrency2015(n, sep, decimals) {
    sep = sep || "."; // Default to period as decimal separator
    decimals = decimals || 2; // Default to 2 decimals
    alert(decimals);
    return n.toLocaleString().split(sep)[0] + sep + parseFloat(n).toFixed(decimals).split(sep)[1];
}

formatCurrency2016(9.1234567899, 9) --> 9.123456790
*/
function formatCurrency2016(num, decimals) {
    var sign = (num >= 0) ? 1 : -1;
    //return (Math.round((num * Math.pow(10, decimals)) + (sign * 0.01)) / Math.pow(10, decimals)).toFixed(decimals);
    return (Math.round((num * Math.pow(10, decimals)) + (sign * 0.001)) / Math.pow(10, decimals)).toFixed(decimals);
}

Imports System
Imports System.Collections.Generic
Imports System.ComponentModel
Imports System.Text
Imports System.Web
Imports System.Web.UI
Imports System.Web.UI.WebControls

'<DefaultProperty("Text"), ToolboxData("<{0}:WL_Controls.WL_TextBox1 runat=server></{0}:WL_Controls.WL_TextBox1>")>
<ControlBuilder(GetType(System.Web.UI.WebControls.TextBoxControlBuilder)), Designer("System.Web.UI.Design.ControlDesigner"), DefaultProperty("ID"), ToolboxData("<{0}:WL_TextBox runat=server></{0}:WL_TextBox>")> _
Public Class WL_TextBox
    Inherits TextBox

    Public Enum InputType
        Text
        [Integer]
        Number
    End Enum

    Public Enum DisplayDecimal
        None
        One
        Two
        Tree
        Four
        Five
...
...
...
    <Bindable(False), Category("Appearance"), DefaultValue(False), Localizable(True), Description("isUpperCase")>
    Property _isUpperCase() As Boolean
        Get
            If ViewState("_isUpperCase") Is Nothing Then
                Return False
            Else
                Return CType(ViewState("_isUpperCase"), Boolean)
            End If
            'Return DirectCast(ViewState("DisplayAsLiteral"), Boolean)
        End Get
        Set(ByVal Value As Boolean)
            ViewState("_isUpperCase") = Value
        End Set
    End Property

    Protected Overrides Sub RenderContents(writer As System.Web.UI.HtmlTextWriter)
        If _DisplayAsLiteral = True Then 'Default Tag Span
            Dim x As New Literal() With {.ID = Me.ID}
            If _AllowInputType = InputType.Integer Then
                If _DisplayComma Then
                    Me.Text = String.Format("{0:N0}", Val(Me.Text))
                End If
            ElseIf _AllowInputType = InputType.Number Then
                x.Text = Me.Text
            End If
            x.RenderControl(writer)
        Else
            MyBase.RenderContents(writer)
        End If
    End Sub

    Protected Overrides Sub OnInit(e As System.EventArgs)
        If (_AllowInputType <> InputType.Text) AndAlso (_FormatOnblur = True) Then
            If Not MyBase.Page.ClientScript.IsClientScriptIncludeRegistered("WL_Controls_JScript") Then
                MyBase.Page.ClientScript.RegisterClientScriptInclude("WL_Controls_JScript", MyBase.Page.ClientScript.GetWebResourceUrl(MyBase.GetType(), "WL_Controls.WL_Controls.js"))
                'HttpContext.Current.Response.Write("Not Register WL_Controls JScript ท่านจำเป็นต้องลงทะเบียนเพื่อเสียเงิน" & "<br/>")
            End If
            If _AllowInputType = InputType.Integer Then
                MyBase.Attributes("onkeypress") = "var cv = (document.all) ? event.keyCode : event.which; return (cv >=48 && cv <=57);"
                'MyBase.Attributes("onkeypress") = "return integerOnly();"
            End If
            If _AllowInputType = InputType.Number Then
                MyBase.Attributes("onkeypress") = "return numberOnly(this);"
                Dim dec As String = "(this.value);"
                If _AllowDisplayDecimal <> DisplayDecimal.None Then
                    dec = "(this.value, " & _AllowDisplayDecimal & ");"
                    'dec = "(this.value, '.', " & _AllowDisplayDecimal & ");"
                End If
                'MyBase.Attributes("onblur") = "this.value = formatCurrency" & dec
                'MyBase.Attributes("onblur") = "this.value = formatCurrency2015" & dec
                MyBase.Attributes("onblur") = "this.value = formatCurrency2016" & dec                
            End If
        ElseIf (_AllowInputType = InputType.Text AndAlso _isUpperCase = True) Then
            MyBase.Attributes("onkeypress") = "var cv = (document.all) ? event.keyCode : event.which; if (cv!='8' && cv!='0' && cv!='27') {this.value+=String.fromCharCode(cv).toUpperCase(); return false;};"
        End If
        MyBase.OnInit(e)
    End Sub
End Class