in the form i have made there are nearly 10 options for a question which are checkboxes ex= type of operation system = windows, windows xp, etc... i have given different names for all these checkboxes the validation is the user has to select atleast one checkbox. presently i am using the following code which is too long for the browser to process var os1=document.enquiryform.os1.checked where os1 is the value of the operating system and the same for the remaining checkboxes if(!(os1 || os2 || os3 || .... os10)) { alert("Please select any one of the operating systems"); return false } this code works however i would like a more efficient code to do this validation also in the form action i am calling a php file, presently i am reading the value of all the checboxes and concatinating into one variable. the php code is = $os1 = !empty($_POST["os1"]); if($os1) $os1="DOS, "; else $os1= ""; and for the remaining checkboxes $os= $os1.$os2 . .......... os10; please advice about the code in javascript and how to read these checkboxes in php. thanks.