How to use Delete fuction from business logic layer

Question

Currently I'm working on a Windows Project. I have a data access layer and  business logic layer. I made a function of Delete in it. But I don't know how to use it on form. I give an example to understand you.

 

My Insert Coding on form is following-

MasterClothDesign obj = new MasterClothDesign();             // MasterClothDesign is the class of Business Logic Layer

obj.Cloth_Design_Name = txtDesignName.Text;

obj.Save();

 

In Business Logic Layer I made the following function of delete.

 

public void DeleteBy(IDbTransaction txn)

{

new MasterClothDesignData(txn).MasterClothDesignData_DeleteByClothDesignId(Cloth_Design_Id);

}

 

Delete Coding on form is following

private void btnDelete_Click(object sender, EventArgs e)

{

MasterClothDesign obj = new MasterClothDesign();

obj.Cloth_Design_Id = Convert.ToInt32(lblDesignId.Text);

obj.DeleteBy();

 }

It gives the error on DeleteBy.  So how this function should be write on form? Thanks in advance.