function Checkfield() {
txt1=document.form.email.value;

if(document.form.name.value==""){
alert("Please Enter Your Name.");
document.form.name.focus();
return false;
}

else if(document.form.subject.value==""){
alert("Please Enter the Subject field.");
document.form.subject.focus();
return false;
}

else if (txt1.indexOf("@")<2){
alert("Check your Email Address .Please"
+"check the prefix and '@' sign.");
document.form.email.focus();
return false;
}
else if ((txt1.indexOf(".")<1)){
alert("Check your Email Address.\n");
document.form.email.focus();
return false;
}


else if(document.form.comment.value==""){
alert("Please Enter Your Comments");
document.form.comment.focus();
return false;
}
else
return true; 
}