function checkData (){

          if (document.forms[0].EmailAddress.value.length ==0){
         alert("Please enter valid email address.")
         return false}
        if (document.forms[0].EmailAddress.value.length >0){
         i=document.forms[0].EmailAddress.value.indexOf("@")
         j=document.forms[0].EmailAddress.value.indexOf(".",i)
         k=document.forms[0].EmailAddress.value.indexOf(",")
         kk=document.forms[0].EmailAddress.value.indexOf(" ")
         jj=document.forms[0].EmailAddress.value.lastIndexOf(".")+1
         len=document.forms[0].EmailAddress.value.length

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