function checkemail(){
   var str=document.forms[0].email.value
   var filter=/^([\w-]+(?:\.[\w-]+)*)@((?:[\w-]+\.)*\w[\w-]{0,66})\.([a-z]{2,6}(?:\.[a-z]{2})?)$/i
   if (filter.test(str))
    testresults=true
   else{
    alert("Please,enter correct email")
    document.contactform.email.focus()
    testresults=false
   }
   return testresults;
 }

  function checkform(){
      if(document.forms[0].name.value==""){
         alert('Please enter your name');
         return false;
      }
      if(document.forms[0].company.value==""){
         alert('Please enter your company');
         return false;
      }
      if(document.forms[0].phone.value==""){
         alert('Please enter your phone');
         return false;
      }
      if(document.forms[0].zip.value==""){
         alert('Please enter Zip Code');
         return false;
      }
     if(document.forms[0].valuation.value==""){
         alert('Please enter ESTIMATED VALUATION');
         return false;
      }

      return checkemail();
  }