function productscreen() {
                window.open("","product","left=20,top=0,width=420,height=670,resizable=yes,toolbar=no,location=no,directories=no,scrollbars=no")
                } 

function orderscreen() {
                window.open("","order","left=20,top=0,width=650,height=670,resizable=yes,toolbar=no,location=no,directories=no,scrollbars=1")
                } 
function checkData (){
  
           if (document.forms[0].fromemail.value.length ==0){
         alert("Please enter valid email addresses.")
         return false}
        if (document.forms[0].fromemail.value.length >0){
         i=document.forms[0].fromemail.value.indexOf("@")
         j=document.forms[0].fromemail.value.indexOf(".",i)
         k=document.forms[0].fromemail.value.indexOf(",")
         kk=document.forms[0].fromemail.value.indexOf(" ")
         jj=document.forms[0].fromemail.value.lastIndexOf(".")+1
         len=document.forms[0].fromemail.value.length

        if ((i>0) && (j>(1+1)) && (k==-1) && (kk==-1) &&
        (len-jj >=2) && (len-jj<=3)) {
           }
         else {
           alert("Please enter valid email addresses.\n" +
           document.forms[0].fromemail.value + " is invalid.")
           return false}}
}