function validateContactUsForm(form) {
    var frm = form;
    var msg = "";
    
    if (frm.name.value == "") {
      alert("Please provide Name.");
      frm.name.focus();
      return false;
    }
    
    if (frm.email.value == "") {
      alert("Please provide Email Address.");
      frm.email.focus();
      return false;
    }
    
    if (!checkEmail(frm.email)) {
      alert("Please provide valid Email Address.");
      frm.email.focus();
      return false;
    }
    
    if (frm.comments.value == "") {
      alert("Please provide Comments or suggestions.");
      frm.comments.focus();
      return false;
    }
    
    return true;
  }
  
  function isStringValid(w) {
    x1 = /^[a-z\d]{2,15}$/i // only alphanumerics, and length 6-10
    x2 = /[a-z]/i           // a letter present
    x3 = /\d/               // a digit present
    OK = x1.test(w) && x2.test(w) && x3.test(w)
    return OK;
  }
  
  function checkEmail(fld)
  {
  	if(fld.value == ""){
  		return true;
  	}
   	if (fld.value.length = 0) return false;
  	str = fld.value;	
  	re = /(^[A-Za-z0-9_])([A-Za-z0-9_.-]*)@((([A-Za-z0-9_-]{2,})\.){1,3})(([A-Za-z]{2,3})$)/;
  	if ( re.test(str) ) {
  		return true;
  	} else {
  		return false;
  	}
  }