Button Click Events

this is validation in javascript


function validate()
{
    if (document.getElementById("<%=dropcategory.ClientID%>").value == "===Select Category===")
      {
          alert("(*)Select Category TO Upload the File");
                 document.getElementById("<%=dropcategory.ClientID%>").focus();
                 return false;
      }
      if (document.getElementById("<%=DropDownList1.ClientID %>").value == "===Select SubCategory===")
      {
          alert("(*)Select SubCategory TO Upload the File");
                 document.getElementById("<%=DropDownList1.ClientID %>").focus();
                return false;
            }
            if (document.getElementById("<%=txtOwnerId.ClientID %>").value == "===Select Owner ID===") {
                alert("(*)Select OwnerID TO Upload the File");
                document.getElementById("<%=txtOwnerId.ClientID %>").focus();
                return false;
            }

            if (document.getElementById("<%=demo1.ClientID %>").value == "") {
                alert("(*)Select Date Upload the File");
                document.getElementById("<%=demo1.ClientID %>").focus();
                return false;
            }

            if (document.getElementById("<%=txtFileUpload.ClientID %>").value == "")
      {
                 alert("(*) Upload Field should not be blank");
                 document.getElementById("<%=txtFileUpload.ClientID %>").focus();
                return false;
            }
            return true;
}


Behind Code

you should call this event inside of pageload.

cmdAdd.Attributes.Add("OnClick", "return validate(event)");



cmdAdd is the id of button. validate is function name which is used in javascript