function showHideSelection(ths,str){
    var obj=document.getElementById(str);
    if(obj.style.display=='inline'){
        obj.style.display='none';
        tmpStr='[+]'+ths.innerHTML.substr(3);
        ths.innerHTML=tmpStr;
    }else{
        obj.style.display='inline';
        tmpStr='[-]'+ths.innerHTML.substr(3);
        ths.innerHTML=tmpStr;
    }
}