// 文本框(input)(textarea)和select下拉菜单获取焦点(onfocus)(onactivate)时样式改变的实现方法 
    // focusClass :文本框(input)(textarea)获取焦点时的样式 
    // normalClass :文本框(input)(textarea)正常状态下的样式 
    // focusSelect :select下拉菜单onactivate时的样式
    // normalSelect :select下拉菜单无动作时的样式
    function focusInput(focusClass,normalClass,mouseoverClass,mouseoutClass,focusSelect,normalSelect) 
    {
        var elements = document.getElementsByTagName("input");
        if(elements != null)
        {
            for (var i=0; i < elements.length; i++) 
            {
                if (elements[i].type == "text" || elements[i].type == "password")  
                {
                    elements[i].onfocus = function() { this.className = focusClass; };
                    elements[i].onblur = function() { this.className = normalClass; };
                    elements[i].onmouseover = function() { this.className = mouseoverClass; };
                    elements[i].onmouseout = function() {
                    if(this!=document.activeElement)
                     this.className = mouseoutClass;
                    };
                }
            }
        }
        
        var elements2 = document.getElementsByTagName("textarea");
        if(elements2 != null)
        {
            for (var i=0; i < elements2.length; i++) 
            {
                    elements2[i].onfocus = function() { this.className = focusClass; };
                    elements2[i].onblur = function() { this.className = normalClass; };
                    elements2[i].onmouseover = function() { this.className = mouseoverClass; };
                    elements2[i].onmouseout = function() {
                    if(this!=document.activeElement)
                     this.className = mouseoutClass;
                    };
                  
            }
        }
        var elements3 = document.getElementsByTagName("select");
        if(elements3 != null)
        {
            for (var i=0; i < elements3.length; i++) 
            {
                    elements3[i].onactivate = function() { this.className = focusSelect; };
                    elements3[i].onblur = function() { this.className = normalSelect; };
            }
        }
       
    }
    
    
    (function()
    {
	    var onload = window.onload;
	    if(typeof window.onload != 'function')
	    {
		    window.onload = function()
			{
				focusInput('focusInput','normalInput','mouseoverInput','normalInput','focusSelect','normalSelect');
			}
		}
		else
		{
			window.onload = function()
			{
				onload();
				focusInput('focusInput','normalInput','mouseoverInput','normalInput','focusSelect','normalSelect');
			}
		}
	})();