Problem Occuring When i insert the data to database

protected void Btn_Register_Click(object sender, EventArgs e)
    {
        Employee_Register();
    }
    public void Employee_Register()
    {
        try
        {
            int id = Convert.ToInt32(Txt_E_Id.Text);
            string name = Txt_E_Name.Text;
            int age = Convert.ToInt32(Txt_E_Age.Text);
            string gender = "";
            if (RB_Male.Checked)
                gender = RB_Male.Text;
            if (RB_Female.Checked)
                gender = RB_Female.Text;
            string address = Txt_Address.Text;
            string phone = Txt_Phone.Text;
            string qualification = Txt_Qualification.Text;
            string attachment = "~/img/" + imm;
            string designation = DDL_Designation.Text;
            string date1 = Txt_J_Date.Text;
            DateTime dat = DateTime.Parse(date1.ToString());
            string date = dat.ToString("MM/dd/yyyy");
            float salary = float.Parse(Txt_Salary.Text);
            float allowance = float.Parse(Txt_Allavance.Text);
            string cworking = DDL_C_Working.Text;
            string image = Image1.ImageUrl;
            
            SqlCommand cmd = new SqlCommand("insert into EmployeeRegistration(EmpId,EmpName,Age,Gender,Address,Phone,Qualification,Attachment,Image,Designation,JoiningDate,Salary,Allowance,CurrentWorking) values(@empid,@empnam,@age,@gen,@addr,@phon,@qual,@atta,@imag,@desi,@join,@sal,@allow,@curren)", DbConnection.mCon);
            cmd.Parameters.Add("@empid", SqlDbType.Int).Value = id;
            cmd.Parameters.Add("@empnam", SqlDbType.VarChar).Value = name;
            cmd.Parameters.Add("@age", SqlDbType.Int).Value = age;
            cmd.Parameters.Add("@gen", SqlDbType.VarChar).Value = gender;
            cmd.Parameters.Add("@addr", SqlDbType.VarChar).Value = address;
            cmd.Parameters.Add("@phon", SqlDbType.VarChar).Value = phone;
            cmd.Parameters.Add("@qual", SqlDbType.VarChar).Value = qualification;
            cmd.Parameters.Add("@atta", SqlDbType.VarChar).Value = attachment;
            cmd.Parameters.Add("@imag", SqlDbType.VarChar).Value = Image1.ImageUrl;
            cmd.Parameters.Add("@desi", SqlDbType.VarChar).Value = designation;
            cmd.Parameters.Add("@join", SqlDbType.VarChar).Value = date;
            cmd.Parameters.Add("@sal", SqlDbType.Float).Value = salary;
            cmd.Parameters.Add("@allow", SqlDbType.Float).Value = allowance;
            cmd.Parameters.Add("@curren", SqlDbType.VarChar).Value = cworking;
            cmd.ExecuteNonQuery();
            Lbl_Msg.Visible = true;
            Lbl_Msg.Text = "[" + name + "]" + "Registration Successfully Added !";
            Txt_E_Name.Text = Txt_E_Age.Text = Txt_Address.Text = Txt_Phone.Text = Txt_Qualification.Text = DDL_Designation.Text = DDL_C_Working.Text = Txt_J_Date.Text = Txt_Salary.Text = Txt_Allavance.Text = "";
            RB_Male.Checked = false;
            RB_Female.Checked = false;
            Image1.ImageUrl = null;
            
        }
        catch
        {
            string name = Txt_E_Name.Text;
            Lbl_Msg.Visible = true;
            Lbl_Msg.Text = "[" + name + "]" + "Registration Failed !";
        }
    }
    protected void Btn_Cancel_Click(object sender, EventArgs e)
    {
        
    }
    protected void Calendar1_SelectionChanged(object sender, EventArgs e)
    {
        string date = Calendar1.SelectedDate.ToShortDateString();
        DateTime dt1 = DateTime.Parse(date.ToString());
        string dt = dt1.ToString("MM/dd/yyyy");
        Txt_J_Date.Text = dt.ToString();
    }
    protected void Btn_Upload_Click(object sender, EventArgs e)
    {
        img_upload = "~/img/" + FileUpload1.FileName;
        FileUpload1.SaveAs(MapPath(img_upload));
        Image1.ImageUrl = img_upload;
    }
    protected void Btn_Upload1_Click(object sender, EventArgs e)
    {
        img_upload1 = "~/img/" + FU_Attachment.FileName;
        FU_Attachment.SaveAs(MapPath(img_upload1));
        imm = FU_Attachment.PostedFile.FileName;
        Lbl_Msg1.Text = "File name: " + FU_Attachment.PostedFile.FileName + "<br>" + FU_Attachment.PostedFile.ContentLength + " kb<br>" + "Content type: " + FU_Attachment.PostedFile.ContentType;
        
   }