Count textarea character using jquery

//////////////HTML

<asp:TextBox runat="server" ID="txt_StrengthsPCI" CssClass="form-control" Rows="4"

                                        TextMode="MultiLine" Style="resize: none;" onkeypress="return TextArea_MaxCount(this.id,'StrengthsPCI',100);"></asp:TextBox>

/////////////Jquery

function TextArea_MaxCount(txtid, divcnt, maxLength) {

                        var length = $('[id$=' + txtid + ']').val().length;

                        var length = maxLength - length;

                        if (length > 0) {

                            $('#' + divcnt).text(length + ' Left');

                        }

                        else {

                            $('#' + divcnt).text(length + ' Left');

                            return false;

                        }

                    }