Unable to access port at sending sms

Question

Hi, I used GSM Communication and PDU Converter dll file to send sms in my asp.net website. Everything is fine in my localhost. I can easily send sms PC to Mobile in my localhost.

But there is a problem. I couldn't send sms form my website(hosted at hostgator.com). When I want to send sms, it shows error:
 
" GsmComm.GsmCommunication.CommException: Unable to open port COM2: 
System.Security.Permissions.SecurityPermission ---> System.Security.SecurityException: System.Security.Permissions.SecurityPermission at GsmComm.GsmCommunication.SerialPortFixer..ctor(String portName) at GsmComm.GsmCommunication.SerialPortFixer.Execute(String portName) at GsmComm.GsmCommunication.GsmPhone.OpenPort(String portName, Int32 baudRate, Int32 timeout) at GsmComm.GsmCommunication.GsmPhone.Open() --- End of inner exception stack trace --- at GsmComm.GsmCommunication.GsmPhone.Open() at GsmComm.GsmCommunication.GsmCommMain.Open() at BRUR.examiner.smsExaminer.testSendingSms()"
 
May be there is need permission to access port. But how can I do this? Please help me immediate. I need to submit my website today at my university.