se me va el hover

[Patriarka]

lo que me decis InKarC me simplifica el codigo

Código Javascript:

function openDiv(id_div, total_bids, id_shipment){
    if(document.getElementById('dialogBidDetails'+id_div+'_'+id_shipment).style.display == 'table-row'){
        document.getElementById('dialogBidDetails'+id_div+'_'+id_shipment).style.display = 'none';
 
       document.getElementById('bid_'+id_div+'_'+id_shipment).removeAttribute("tr_sin_hover");
    }else{
         for(var i=1; i<=total_bids; i++){
            if(document.getElementById('dialogBidDetails'+i+'_'+id_shipment).style.display == 'table-row'){
             document.getElementById('dialogBidDetails'+i+'_'+id_shipment).style.display = 'none'
             document.getElementById('bid_'+id_div+'_'+id_shipment).removeAttribute("tr_sin_hover");
            }
        }
        document.getElementById('dialogBidDetails'+id_div+'_'+id_shipment).style.display = 'table-row';
       document.getElementById('bid_'+id_div+'_'+id_shipment).removeAttribute("tr_con_hover");
 
       //document.getElementById('bid_'+id_div+'_'+id_shipment).style.background= 'lightgray';
        //document.getElementById('bid_'+id_div+'_'+id_shipment).style.backgroundImage= "url(<?php echo $myConfig->website_url;?>images/bg_table_presupuestos_on.jpg)";
 
    }
}
 

pero no logro que quede con el estilo hover el tr seleccionado

uso estos estilos

Código CSS:

.tr_sin_hover{  background:white; background-image:url(../images/bg_table_presupuestos.jpg); background-repeat:repeat-x; background-position:bottom;  }
.tr_con_hover{  background:lightgray; background-image:url(../images/bg_table_presupuestos_on.jpg);  }