DDEOpen Error

I am receiving the error "An error occurred while executing 24x7 script Line 31:" Below is the code up to this point. It is a problem with the DDEOpen statement. We are using the Windows version 3.26.

// declare script variables
Dim( job_list, string )
Dim( no_more, boolean )
Dim( job_id, string )
Dim( job_script, string )
Dim( job_script_msg, string )
Dim( job_script_msg_ori, string )
Dim( job_script_ori, string )
Dim job_script_msg_code string
dim job_script_msg_code_ori string
Dim( script_changes, boolean)
Dim( msg_changes, boolean)
Dim( i number)
Dim global.count number
Dim (result, string)
Dim (file_number, number)
Dim Comment string
Dim note_changes boolean
dim job_name string
dim MSG_EMAIL string
dim MSG_EMAIL_Y boolean

dim( global.channel, number)

Set (i, 0)
Set (global.count, 0)

//DDEOpen("24x7 Scheduler", "JDL", global.channel)
Dim(what, string)
Dim(channel, number)
DDEOpen("24x7 Scheduler", "JDL", channel)

Did you mean version 3.4.26? Please enable tracing and check what you get in interface.log file.

Somehow there was a DDE connection open. It is working now. Thanks for the hint.