function change_tableRows_color(){
	if(document.getElementsByTagName){  
		var tables = document.getElementsByTagName("table");
		for(i=0; i<tables.length; i++){
			var table = tables[i];
			var rows = table.getElementsByTagName("tr");  
			for(j = 0; j < rows.length; j++){          
				if(j % 2 == 0){
					rows[j].className = "even_row";
				}else{
					rows[j].className = "odd_row";
				}      
			}
		}		
	}
}