Request letter for my salary increment

Sir I'm working this company from July 2010 (more then 8 yrs)profession for driver

Now my work customs representative and staff pick and drop & pro work all other work

Starting salary 3000 Dhs

Now thare paying 3500 Dhs only

Not increased morethan 5yrs

Now I hw wife and daughter

This salary Low for staying with family hare

Please help me to make request letter for my boss