function contact_us()
{
//alert("contact_us");
	 if(!is_blank())
	{
	 return false;
	} 
	var email=document.myform.email.value;
	if(!echeck(email))
	{
	  document.myform.email.focus()
	  return false;
	}
	var phone=document.myform.phone.value;
	if(!IsNumeric(phone))
	{
	   document.myform.phone.focus()
	  alert("Invalid Phone No");
			   return false;
	}
 return true;
}
//--------------------------------------------------------------------------
function echeck(str) {
  //alert("you are in echeck function"+str);
		var at="@"
		var dot="."
		var lat=str.indexOf(at)
		var lstr=str.length
		var ldot=str.indexOf(dot)
		if(str=='')
		{
		 alert("Please enter your E-mail");
		 
		 return false;
		}
		if (str.indexOf(at)==-1){
		   alert("Invalid E-mail ID")
		  	return false
		}

		if (str.indexOf(at)==-1 || str.indexOf(at)==0 || str.indexOf(at)==lstr){
		   alert("Invalid E-mail ID")
		   
		   return false
		}

		if (str.indexOf(dot)==-1 || str.indexOf(dot)==0 || str.indexOf(dot)==lstr){
		    alert("Invalid E-mail ID")
			 return false
		}

		 if (str.indexOf(at,(lat+1))!=-1){
		    alert("Invalid E-mail ID")
            return false
		 }

		 if (str.substring(lat-1,lat)==dot || str.substring(lat+1,lat+2)==dot){
		    alert("Invalid E-mail ID")
			 return false
		 }

		 if (str.indexOf(dot,(lat+2))==-1){
		    alert("Invalid E-mail ID")
			return false
		 }
		
		 if (str.indexOf(" ")!=-1){
		    alert("Invalid E-mail ID")
		    return false
		 }

 		 return true					
	}
	//-------------------------------------------------------------------------------------------
	function is_blank()
{ 
//alert("isblank");
	 if(document.myform.name.value=='')
	 {
	   alert("Please enter your name");
	   document.myform.name.focus()
			return false
	 }
	  if(document.myform.school.value=='')
	 {
	   alert("Please enter your school");
	   document.myform.school.focus()
			return false
	 }
	  if(document.myform.address.value=='')
	 {
	   alert("Please enter your address");
	   document.myform.address.focus()
			return false
	 }	 
	 
		return true;
}
//------------------------------------------------------------------------------------------------------
function IsNumeric(strString)	
   {
   //alert("IsNumeric");
   var strValidChars = "0123456789+- ";
   var strChar;
   var blnResult = true;

   if (strString == "")
	   {
			alert("Please Enter Phone Number.");
			return false;
	   }

   //  test strString consists of valid characters listed above
   for (i = 0; i < strString.length && blnResult == true; i++)
      {
      strChar = strString.charAt(i);
      if (strValidChars.indexOf(strChar) == -1)
         {
         blnResult = false;
         }
      }
   return blnResult;
   }
   //---------------------------------------------------------------------------------------------------------