JS输入格式判断

function checkLogin()
{ if($("txtUsername").value==""){ alert("对不起用户名不能为空！"); document.all.txtUsername.focus(); return false; }
else if(!isRight($("txtUsername").value)){ alert("用户名不允许包含引号( ')！"); document.all.txtUsername.focus(); return false; }
else if($("txtPassword").value==""){ alert("对不起密码不能为空！"); document.all.txtPassword.focus(); return false; }
else if($("txtPassword").value!=$("txtPassword2").value){ alert("两次输入密码不一致！"); document.all.txtPassword2.focus(); return false; }
else if(!chkemail($("txtEmail").value)){ alert("Email邮箱地址格式不正确！"); document.all.txtEmail.focus();
return false; }
else if(!isRight($("txtEmail").value)){ alert("Email邮箱地址不允许包含引号( ')！"); document.all.txtEmail.focus(); return false; }
return true; }
function isRight(str){ if ((str == null)||(str == "")){ }
else{ var len = str.length; for(var i = 0; i < len; i++)
{ if (str.charAt(i)=="'")
{ return false;}}} return true; }
function chkemail(stremail)
{ if(stremail.indexOf('@') >= 0 && stremail.indexOf('.') >=0)
{ return true;}
return false; }