INPUT type=image 自动提交表单

today when i write the system logon code,i write the code like :

 

<input type="image" tabindex="4" name="imageField" id="imageField"
        src="<%=baseURL %>/css/style/HCS_Style/image/HCS_Style/login2_04.gif" onclick="javascript:login();" />;

 

so the confusing thing come,when i click the image the form is automatically submit;

so the above code submit the form twice.

i check the html conference, i find a sentence like this:

"INPUT type=image 创建一个图像控件，该控件单击后将导致表单立即被提交。"

that is to say:Creates an image control that, when clicked, causes the form to be immediately submitted.

 

so you can write the logon code like below formats:

1.<img tabindex="4" name="imageField" id="imageField" src="<%=baseURL %>/css/style/HCS_Style/image/HCS_Style/login2_04.gif" style="cursor:hand"  onclick="javascript:login()">

2.<input type="image" tabindex="4" name="imageField" id="imageField"
        src="<%=baseURL %>/css/style/HCS_Style/image/HCS_Style/login2_04.gif"  />;

when you write the code like the second fomat,you must set the action to the form before the image is clicked.