Connecting Another Databases from crm javascript + sql

When creating account, we need control, if an account number exist in another database, for controlling this case, we write sql code in javascript.

function erpFirmaKontrol(val) {

var conn = new ActiveXObject("ADODB.Connection");
var kontrol=0;
var constr = "Provider=sqloledb;Data Source=dataservername; Initial Catalog=databasename;User Id=username;Password=password;"
conn.Open (constr);
query="select FirmaAdi from BM_ERP_Genel.dbo.Firmalar where FirmaGrupId=2 and firmakodu='"+val+"'";
var rs = new ActiveXObject("ADODB.Recordset")
rs.open(query, conn,3,3)
if(!rs.bof) {
rs.MoveFirst()
while(!rs.eof) {
kontrol=rs.fields("FirmaAdi").value;
rs.MoveNext()
}
}
rs.close()
return kontrol;
}