For Ruth Russell, Friday isn't just another workday . It's the one day she can wear a sweater and casual slacks instead of a business suit. An employee at an insurance company, Russell loves the day away from her usual dressy suits and high heeled shoes:'' It's a real treat. It puts us in a good mood and winds the week down." Russell has joined thousands of workers across the United States who happily change from jackets, ties, and dresses to jeans, polo shirts, and sweaters on Fridays.