SQL Server Query in C#

private void textBox10_TextChanged(object sender, EventArgs e)

{

SqlConnection cn = new SqlConnection("....");

SqlDataAdapter da = new SqlDataAdapter("Select * from admission where stenroll like '" + textBox1.Text + "%' or stname like '" + textBox10.Text+ "%' or fname like '" + textBox3.Text + "%' or gender like '" + comboBox1.SelectedValue.ToString() + "%' ", cn);

 

DataTable tbl = new DataTable()

 

I dont whats is wrong.