IT 0009 payment method

Dear Experts,

I am not able to remove / hide unused payment mehtods from the drop down list in IT0009 presently there are 3 types ie.,

Blank: Cash payment

E : Cash Payment

T : Bank Transfer

presently we are using Balank for Cash paymen.,t and users are cofused with E so i have to remove / hide "E" from the list

Please guide me how can i do this

early replys are highly appriciated

Thanks in Advance

Sanm