How to declare scalar variable?

Question

I get this error:

System.Data.SqlClient.SqlException: 'Must declare the scalar variable "@refSlips".'

Code:

SqlConnection con = new SqlConnection(connectionString);

SqlCommand aaa = new SqlCommand("INSERT INTO ConsultationTB VALUES('" + consultationTb.Text + "','" + dateTb.Text + "','" + bodytempTb.Text + "','" + paccodeTb.Text + "', @refSlips ", con);

string RadButt = string.Empty;

if (ForAdmission.Checked)
{
    RadButt = "For Admission";
}
else if (ForLabTest.Checked)
{
    RadButt = "For Laboratory Test";
}
else if (BothRb.Checked)
{
    RadButt = "Both";
}
else if (NotAppRb.Checked)
{
    RadButt = "Not Applicable";
}
     
con.Open();
aaa.ExecuteNonQuery();
con.Close();

getCONNO();

ForAdmission.Checked = false;
ForLabTest.Checked = false;
BothRb.Checked = false;
NotAppRb.Checked = false;

Answer 1

[ + "', @refSlips)" , con);] the problem was the parenthesis after refslips.