Created Element Not Inheriting Css Class Formatting?

I'm using something along the lines of...

Code:
//next we need to create a row
workingTR = workingTable.insertRow(position+i);
// then I use setAttribute to set the class

[Code]....

the row (tr) is being assigned the class of employee-detail, and I've confirmed this by looking throught the dom explorer. however, it's NOT inherting the CSS formating that is located in a external file .css. I hard coded in a row with the same class 'employee-detail' and it inherited the css formatting.

I'm wondering why my javascript created row is not inheriting the css class formatting.

Code:
.employee-detail {
font-size:10px;
font-weight:bold;
}