How to enter 200 word only in multiline textbox using java script

<script language="javascript" type="text/javascript">
        function tsize(x1) {
            var w1 = x1.value.split(" ");
            var b1 = w1.length;
            if (b1 > 200) {
                alert("You can not enter more than 200 Words.\nYou have entered " + b1 + " Words.");
                //x1.value="";
                x1.focus();
                return false;
            }
            else
                return true;
        }

        function limiter1(tt1) {
            var lenchar;
            var tax = tt1.value.split(" ");
            var len = tax.length;
            var count = 200;
            if (len > count) {
                //alert("You can not enter more than 200 Words.\nYou have entered "+len+" Words.");
                //tt1.focus();  
                var tax1 = tt1.value;
                lenchar = tax1.length;
                tax1 = tax1.substring(0, lenchar - 1);
                tt1.value = tax1;
                return false;
            }
            document.getElementById("<%=limit1.ClientID%>").value = count - len;

        }

    </script>


 <asp:TextBox ID="txtProductDescription" runat="server" Width="250px" TextMode="MultiLine"
                                            Height="100px" onblur="tsize(this)" onKeyUp="limiter1(this)"></asp:TextBox>
                                        <asp:RequiredFieldValidator ID="RequiredFieldValidator5" runat="server" ErrorMessage="Please enter description"
                                            ControlToValidate="txtProductDescription">*</asp:RequiredFieldValidator>
<asp:TextBox ID="limit1" runat="server" size="1"></asp:TextBox>&nbsp;&nbsp;&nbsp;No
                                        of words left