i got the solution... by adding style="word-wrap:break-word;" to label and removing the height property of label can achieve tht
<asp:Label ID="LblDescription" runat="server"
Font-Bold="True" Font-Names="Verdana"
Font-Size="X-Small" ForeColor="#0061C1" Height="16px"
Width="97px" BorderColor="#0061C1"
BorderWidth="1px" style="word-wrap:break-word;" BackColor="White"></asp:Label>