Change SqlCommand Based On Combo Box Selection

I have a textbox, combo box, and a button on a form.  I would like to perform a different query depending on the combo box selection.  I thought I could do something such as: if (cboSearch.Text == "Selection1")
{
scCmd = "SELECT * FROM tblTable WHERE txtSearch = @Selection1";
}
else if (cboSearch.Text == "Selection2")
{
scCmd = "SELECT * FROM tblTable WHERE txtSearch = @Selection2";
}
else
{
scCmd = "SELECT * FROM tblTable WHERE txtSearch = @Selection3";
} However, this obviously does not operate as I would need it to.  What is the proper method for conditional SqlCommand statements like this?