How do i use function fnPriority more times?

 function fnPriority( a )
		{
			if ( a == 'mega' )        { return 1; }
			else if ( a == 'giga' ) { return 2; }
			else if ( a == 'tera' )    { return 3; }
			return 0;
		}

function fnPriority( a )
		{
			if ( a == 'slow' )        { return 1; }
			else if ( a == 'normal' ) { return 2; }
			else if ( a == 'fast' )    { return 3; }
			return 0;
		}
		
		
		jQuery.fn.dataTableExt.oSort['priority-asc']  = function(a,b) {
			var x = fnPriority( a );
			var y = fnPriority( b );
			
			return ((x < y) ? -1 : ((x > y) ? 1 : 0));
		};
		
		jQuery.fn.dataTableExt.oSort['priority-desc'] = function(a,b) {
			var x = fnPriority( a );
			var y = fnPriority( b );
			
			return ((x < y) ? 1 : ((x > y) ? -1 : 0));
		};