ASPX Code......
<script type="text/javascript" src="calendar/calendar.js"/>
<script type="text/javascript" src="calendar/calendar-en.js"/>
<script type="text/javascript" src="calendar/calendar-setup.js"/>
<script type="text/javascript" language="javascript">
function InitCalendars()
{
Calendar.setup
(
{
inputField : "txtFromDate", // id of the input field
//ifFormat : "%d-%mm-%Y", // format of the input field
ifFormat : "%m/%d/%Y",
button : "btnFromDate", // trigger for the calendar (button ID)
align : "Tl", // alignment (defaults to "Bl")
singleClick : true
}
);
Calendar.setup
(
{
inputField : "txtToDate", // id of the input field
//ifFormat : "%d-%mm-%Y", // format of the input field
ifFormat : "%m/%d/%Y",
button : "btnToDate", // trigger for the calendar (button ID)
align : "Tl", // alignment (defaults to "Bl")
singleClick : true
}
);
return false;
}
</script>
<body onload="InitCalendars();">
<asp:Label ID="lblFromDate" runat="server" Text="From:" Font-Bold="False" Font-Size="Small"></asp:Label>
<asp:TextBox ID="txtFromDate" runat="server" AutoPostBack="True" Font-Names="Arial" Font-Size="10pt" OnTextChanged="txtFromDate_TextChanged" Width="115px"></asp:TextBox>
<img id="btnFromDate" runat="server" alt="Pick Date" height="16" onmouseover="this.style.cursor='hand'" src="Images/datePick.gif" width="16" />
<asp:Label ID="lblTo" runat="server" Font-Bold="False" Font-Size="Small" Text="To:"></asp:Label>
<asp:TextBox ID="txtToDate" runat="server" AutoPostBack="True" Font-Names="Arial" Font-Size="10pt" OnTextChanged="txtToDate_TextChanged" Width="115px"></asp:TextBox>
<img id="btnToDate" runat="server" alt="Pick Date" height="16" onmouseover="this.style.cursor='hand'" src="Images/datePick.gif" width="16" />
</body>
ASPX.CS code....
protected void txtFromDate_TextChanged(object sender, EventArgs e)
{
string fromDateString = txtFromDate.Text;
DateTime startDate = Convert.ToDateTime(fromDateString);
string toDateString = txtToDate.Text;
DateTime endDate = Convert.ToDateTime(toDateString);
if (DateTime.Compare(startDate, endDate) > 0)// May be your another condition
{
Page.RegisterStartupScript("javascript", "<script>alert('\"From date\" must be less than \"To date\"')</script>");
txtToDate.Text = fromDateString;
}
else
{
// Your further code
}
}
I have attached "Try this.zip" for your reference.