HTML & Java script doubt..

Hi friend, sorry for putting this question to php-list. Here I am getting the error as "Object doesn't support this property or method" in line number 22. ============================ <html> <head> <script language="javascript"> function checkall() { var n=0,i=document.form1.OptionList.length; while(n<i) { document.form1.OptionList[n].checked=true; n=n+1; } } </script> </head> <body bgcolor="#FFFFFF" text="#000000"> <form name="form1" method="post" > <input type="checkbox" name="OptionList[]" value="something1">Option 1</input><br> <input type="checkbox" name="OptionList[]" value="something2">Option 2</input><br> <input type="checkbox" name="OptionList[]" value="something3">Option 3</input><br> <input type="checkbox" name="checkall" OnClick=checkall()> /////////This is error line </form> </body> </html> ================================== Thanks and Regards Balaji

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