How to send email with hyperlink

public void SendEmail(OEMaster oe, int actionType, string accept)
        {
            try
            {
                string mailTo = string.Empty;
                string mailFrom = string.Empty;
                string mailCC = string.Empty;
                string mailSubject = string.Empty;

                string mailMessage = "Dear Concern,";
                mailMessage += "<br />";
                mailMessage += "<br />";

                switch (actionType)
                {
                    case 1:////Mail From Requester to Line Manager for Approval of Advance Expense Request
                        #region Mail Body
                        mailSubject = "Advance Expense Request.";
                        mailTo = oe.Approver.Email; // this.GetEmailAddress(oe.ApproverID);
                        mailMessage += string.Format("This mail informs you that the following person has submitted his Advance Expance request for your approval. Please logon to Prottasha and approve it through Advance Expence Approver menu.");
                        mailMessage += "<br />";
                        mailMessage += "<br />";
                        mailMessage += "The Details are as follows:";
                        mailMessage += "<br />";
                        mailMessage += "<br />";
                        mailMessage += "Employee: " + oe.Employee.Name;
                        mailMessage += "<br />";
                        mailMessage += "<br />";
                        mailMessage += "Amount:  " + oe.Amount;
                        mailMessage += "<br />";
                        mailMessage += "Required Date:  " + oe.RequireDate;
                        mailMessage += "<br />";
                        mailMessage += "Advance For:  " + oe.Expense.Description;
                        mailMessage += "<a href="http:www.google.com"></a>";

                        #endregion
                        break;