IE中Ext的comboBox跑到页面左上角详解编程语言

{ 
     xtype:'combo', 
     width:100, 
     //id:'exTypeCom', 
     name:'exType', 
     hiddenName:'exType', 
     displayField:'text', 
     valueField:'value', 
     editable:true, 
     forceSelection:true, 
     triggerAction:'all', 
     mode:'local', 
     store:examine_type_store 
    }