how to compare two text boxes in c#.net?

<asp:textbox id="txtConfirmPassword" validationgroup="a" cssclass="textbox" textmode="Password" xmlns:asp="#unknown">
                                             runat="server" Columns="20"></asp:textbox>

<asp:comparevalidator enableviewstate="false" display="None" validationgroup="a" xmlns:asp="#unknown">
                                             ControlToValidate="txtConfirmPassword" runat="server" ErrorMessage="Your passwords do not match. Please type more carefully."
                                             ID="CompareConfirm" ControlToCompare="txtNewPassword">
                                         </asp:comparevalidator>

<ajaxToolkit:ValidatorCalloutExtender EnableViewState="false" ID="ValidatorCalloutExtender5"
                                              TargetControlID="CompareConfirm" HighlightCssClass="validatorCalloutHighlight"
                                              runat="server">
                                          </ajaxToolkit:ValidatorCalloutExtender>

Private Function ChangePassword() As Boolean
        Try
            Dim strMSG As String = ""
            Dim intError As Integer = 0
            If txtOldPass.Text.Trim.Equals("") Then
                strMSG = "Old password can't be blank"
                intError = 1
            ElseIf txtNewPass.Text.Trim.Equals("") Then
                strMSG = "New password can't be blank"
                intError = 1
            ElseIf txtConNewPass.Text.Trim.Equals("") Then
                strMSG = "Confirm password can't be blank"
                intError = 1
            ElseIf Not txtOldPass.Text.Trim.Equals(strOLDPassword) Then
                strMSG = "Old Password is incorrect"
                intError = 1
            ElseIf Not txtNewPass.Text.Trim.Equals(txtConNewPass.Text.Trim) Then
                strMSG = " New Password and Confirm New Password do not Match"
                intError = 1
            ElseIf txtNewPass.Text.Trim.Length < 6 Then
                strMSG = "New password can't be less than 6 characters"
                intError = 1
            ElseIf txtNewPass.Text.Trim.Equals(strOLDPassword) Then
                strMSG = "New password can't be same as old password"
                intError = 1
            End If
            If intError = 1 Then
                MessageBox.Show(strMSG, "Change Password", MessageBoxButtons.OK, MessageBoxIcon.Information)
                Return False
            End If

            Dim arrColName As New ArrayList
            Dim arrRowData As New ArrayList
            arrColName.Add("UM_VC30_Password")
            arrRowData.Add(Encrypt(txtNewPass.Text.Trim))

            Dim strSelectSQL As String
            strSelectSQL = "select * from table where UM_IN4_Address_No_FK=" & cbUserName.SelectedValue

            If objWS.Update(PropConString, "Table", strSelectSQL, arrColName, arrRowData, "frm_ChangePassword-ChangePassword-75") = True Then
                MessageBox.Show("Password Changed Successfully", "Password Changed", MessageBoxButtons.OK, MessageBoxIcon.Information)
                strOLDPassword = txtNewPass.Text.Trim
                txtOldPass.Text = ""
                txtNewPass.Text = ""
                txtConNewPass.Text = ""
                Return True
            Else
                MessageBox.Show("Please Try Later", "Try Later", MessageBoxButtons.OK, MessageBoxIcon.Error)
                Return False
            End If
            Return True
        Catch ex As Exception
            XYZ.Logging.EventLogging.CreateLog("frm_ChangePassword", "ChangePassword-88", LogType.Application, LogSubType.Exception, ex.TargetSite.Attributes, ex.ToString, PropUserID, PropUserName)
        End Try

    End Function

Private Sub btnChange_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnChange.Click
     ChangePassword()
 End Sub

public bool IsPasswordsEqual(string password1, string password2)
{
	if (password1.Equals(password2))
        {
		return true;
	}

	return false;
}

if(!IsPasswordsEqual(Textbox1.Text,TextBox2.Text))
{
MessageBox.Show("Enter same password in both");
}