Collection of methods to determine whether a radio button or check box is selected in javascript_Form special effects

Tip: The getElementsByName method is used to obtain a collection of objects based on the value of the NAME tag attribute.
Sample 1

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Tip: The getEmentsByName method works based on the value of the NAME tag attribute Gets a collection of objects.


Sample 2:

<script>... <BR>function check()...{ <BR> var flag=0 <BR> for(i=0;i<myform.picno.length;i++) <BR> if(myform.picno[i].checked==true)...{ <BR> flag=1 <BR> break <BR> } <BR> if(!flag)...{ <BR> alert("请先选择更换图片的位置") <BR> return false <BR> } <BR>} <BR></script>