Date Validation for JavaScript

The below code is check-in entering string is current date or previous date, the previous date did not include Saturday and Sunday.

 

ASPX Page

<aspx:TextBox runat="server" id="txtvalid" ></asp:TextBox>
lt;asp:Button ID="btnsave" Text="Create User" runat="server" OnClientClick="dateValidation(this);"/>

Script

function dateValidation(evt) {
    var d = new date();
    var n = d.getDay();
    var text = document.getElementById("txtvalid").value;
    var today = new date();
    var dd = today.getDate();
    var mm = today.getmonth() + 1;
    var yyyy = today.getFullYear();
    if (dd < 10) {
        dd = '0' + dd
    }
    if (mm < 10) {
        mm = '0' + mm
    }
    today = dd + '/' + mm + '/' + yyyy
    if (n = 1)
        var yest = dd - 3;
    else
        var yest = dd - 1;
    var yestrday = yest + '/' + mm + '/' + yyyy
    if (text != today && (text != yesterday)) {
        alert('Please Enter current date or previous date'
        }
    }
}

Thanks Sreejesh