function form_check() {

	  invalidChars=' #$%^&*()=+/:,;';
	  Email=document.getElementById('email').value;
		
	  if(Email == '') {
		  alert('type your e-mail');
		  return false;
	  }
		
	  for (i=0;i<invalidChars.length;i++) {
		  badChar=invalidChars.charAt(i);
		  if (Email.indexOf(badChar,0)>-1) {
			   alert('do not use #$%^&*()=+/:,;');
			   return false;					
		  }
	  }
		
	  atPos=Email.indexOf('@',1);
	  if (atPos==-1) {
			   alert('wrong e-mail value');
			   return false;					
		  }
		
	  if (Email.indexOf('@',atPos+1)>-1) {
			   alert('wrong e-mail value');
			   return false;					
		  }
		
	  periodPos=Email.indexOf('.',atPos);
		
	  if (periodPos==-1) {
			   alert('wrong e-mail value');
			   return false;					
		  }
		
	  if (periodPos+3>Email.length) {
			   alert('wrong e-mail value');
			   return false;					
		  }
	  if(document.getElementById('pword').value == '') {
		   alert('please type password');
		   return false;
	  }
	  if(document.getElementById('first').value == '') {
		   alert('please type your first name');
		   return false;
	  }
	  if(document.getElementById('last').value == '') {
		   alert('please type your last name');
		   return false;
	  }
	  if(document.getElementById('phone').value == '') {
		   alert('please type your phone');
		   return false;
	  }	  
  			  	  	  	  	  	  	  
	  return true;

 }