mehwish

[b]
I would like to invite my parents to visit canada. My father is an employee back home . I have read the documents needed for temporary visit to canada.It clearly says that they need the employers letter alongwith the form. The problem is my dad cannot arrange the employer's letter as this will create some problem at his job . He has other proof to show that he is employed like his payslip etc. If visa is granted he'll leave the country within 3 weeks since i have other siblings back home .
My question is : Is this ok if he attach other proof of his job instead of the employer's letter??Will it cause any delays or objection to grant temporary visa???