//以下是页面切换代码
function switchmodTag(modtag, modcontent, modk, modcount) {
    for (i = 1; i < modcount; i++) {
        if (i == modk) {
            document.getElementById(modtag + i).className = "menuOn"; document.getElementById(modcontent + i).className = "slidingList";
        }
        else {
            document.getElementById(modtag + i).className = "menuNo"; document.getElementById(modcontent + i).className = "slidingList_none";
        }
    }
}

        function bookmark(title, url) { 
            if (document.all)
                window.external.AddFavorite(url, title);
            else if (window.sidebar)
                window.sidebar.addPanel(title, url, '')
        }
   

// 1.判断select选项中 是否存在Value="paraValue"的Item 
function jsSelectIsExitItem(objSelect, objItemValue) { 
var isExit = false; 
    for (var i = 0; i < objSelect.options.length; i++) { 
        if (objSelect.options[i].value == objItemValue) { 
            isExit = true; 
            break; 
        } 
    } 
    return isExit;
} 

// 2.向select选项中 加入一个Item 
function jsAddItemToSelect(objSelect, objItemText, objItemValue) { 
//判断是否存在 
    if (!jsSelectIsExitItem(objSelect, objItemValue)) { 
        var varItem = new Option(objItemText, objItemValue); 
            objSelect.options.add(varItem);         
    } 
} 


// 3.从select选项中 删除一个Item 
function jsRemoveItemFromSelect(objSelect, objItemValue) { 
//判断是否存在
    if (jsSelectIsExitItem(objSelect, objItemValue)) {
        for (var i = 0; i < objSelect.options.length; i++) {
            if (objSelect.options[i].value == objItemValue) {
                objSelect.options.remove(i);
                break;
            }
        }
    }
} 


// 4.删除select中选中的项 
function jsRemoveSelectedItemFromSelect(objSelect) { 
var length = objSelect.options.length - 1; 
    for(var i = length; i >= 0; i--){ 
        if(objSelect.options[i].selected == true){ 
            objSelect.options[i] = null; 
        } 
    } 
} 

// 5.修改select选项中 value="paraValue"的text为"paraText" 
function jsUpdateItemToSelect(objSelect, objItemText, objItemValue) { 
//判断是否存在 
if (jsSelectIsExitItem(objSelect, objItemValue)) { 
    for (var i = 0; i < objSelect.options.length; i++) { 
        if (objSelect.options[i].value == objItemValue) { 
            objSelect.options[i].text = objItemText; 
            break; 
        } 
    } 
   } 
} 

// 6.设置select中text="paraText"的第一个Item为选中 
function jsSelectItemByValue(objSelect, objItemText) { 
//判断是否存在 
    var isExit = false; 
    for (var i = 0; i < objSelect.options.length; i++) { 
        if (objSelect.options[i].text == objItemText) { 
            objSelect.options[i].selected = true; 
            isExit = true; 
            break; 
            } 
    } 
}