function FocusButtonSearch(e, prefix) 
{ 
    var keynum  
    var keychar  
    var numcheck 
  
    if(window.event) // IE  
    { 
        keynum = e.keyCode  
    } 
    else if(e.which) // Netscape/Firefox/Opera  
    { 
        keynum = e.which  
    } 
    
    keychar = String.fromCharCode(keynum) 
    if (keynum == 13) {
        if(document.getElementById(prefix + '_search_param').value != '') {
            //document.getElementById(prefix + '_search_button').focus();
            document.getElementById(prefix + '_search_button').click();
        }
        return false;  
    } else {
        return true; 
    }
}