C#

string sql = "SELECT * FROM Users WHERE UserName = '" + txtUserName.Text "' AND Password = '" + txtPassword.Text + "'";
OleDbCommand cmd = new OleDbCommand(cmd, conn);

string sql = "SELECT * FROM Users WHERE UserName = ? AND Password = ?";
OleDbCommand cmd = new OleDbCommand(cmd, conn);
cmd.Parameters.Add("", txtUserName.Text);  // In Access, parameter name doesn't
cmd.Parameters.Add("", txtPassword.Text);  // matter, it's by position

double d = 0.0;
 
try
{
    d = Convert.ToDouble(textBox.Text);
}
catch(FormatException)
{
    // Error parsing the double... invalid characters maybe?
}
 
// Do whatever with d (that will contain 0 if an error occurred.)

<br />
...<br />
DB2Parameter[] db2params = new DB2Parameter[3];<br />
<br />
BuildParameters(db2params, new object[] {"LSFEEDCD", DB2Type.Char, 4,"RABF"} , new object[]{"LSINVDT", DB2Type.Date, 8,"20041100"},new object[]{"LSSQLCD", DB2Type.SmallInt, 2,20});<br />
<br />
DB2Helper.FillDataset(txtConnectionString.Text,"TTEZQ.ZQSPNS4", ds, new string[] {"Gateway_Test"},db2params);<br />
...<br />
..<br />

<br />
  public static void BuildParameters(DB2Parameter[] DB2Params, params object[] parameters)<br />
   {<br />
	   for (int i=0; i <parameters.Length;i++)<br />
	   {<br />
		   object a = ((object[])(object)parameters[i])[0];<br />
		   object b = ((object[])(object)parameters[i])[1];<br />
   		   object c = ((object[])(object)parameters[i])[2];<br />
   		   object d = ((object[])(object)parameters[i])[3];<br />
		   DB2Params[i] = new DB2Parameter((string)a,(IBM.Data.DB2.DB2Type)b,(int)c);<br />
		   DB2Params[i].Direction = ParameterDirection.InputOutput;<br />
   		   DB2Params[i].Value = d;<br />
	   }<br />
   }<br />

DB2Command cmd = new DB2Command("proc name", conn);
cmd.CommandType = CommandType.StoredProcedure;
cmd.Parameters.Add("InOutParam", inputValue).Direction = ParameterDireciton.InputOutput;
 
DB2DataAdapter da = new DB2DataAdapter(cmd);
da.Fill(ds);  // Execute the stored procedure and get the returned data sets
 
// Get value of output parameter, cast to whatever type
int outputValue = (int) cmd.Parameters[0].Value;

foreach( string s in arrayListOfStrings )
    Console.WriteLine( "The list contains {0}", s );