Something

function is_empty(theField){	if (theField.value ==""|| theField.value==null|| theField.value==0) {	alert('Please enter your ' + theField.name);     theForm.focus();	return false;	}	else return true;}function validateForm(theForm) {var flag = !is_empty(theForm.name);if(flag) flag = !is_empty(theForm.name);if(flag) flag =!is_empty(theForm.age);if(flag) flag = !is_empty(theForm.sex);if(flag) flag = !is_empty(theForm.city);if(flag) flag = !is_empty(theForm.email);return flag;}