JS：Trim() in javascript, how to define a function of checkinput for a WebControl(ascx)

//去除字串兩端空格,用法是string.Trim()
String.prototype.Trim = function()
{
 return this.replace(/(^/s*)|(/s*$)/g, "");
}

function CheckInput()
{
 //驗證名稱
 document.Form1.AddMessage1_MessageTitle.value == document.Form1.AddMessage1_MessageTitle.value.Trim();
 if(document.Form1.AddMessage1_MessageTitle.value == "")
 {
  alert("請輸入留言標題");
  event.cancelBubble=true;
  event.returnValue=false;
  document.Form1.AddMessage1_MessageTitle.focus();
  return false;
 }
 
 //驗證留言內容
 document.Form1.AddMessage1_Content.value == document.Form1.AddMessage1_Content.value.Trim();
 if(document.Form1.AddMessage1_Content.value == "")
 {
  alert("請輸入留言內容");
  event.cancelBubble=true;
  event.returnValue=false;
  document.Form1.AddMessage1_Content.focus();
  return false;
 }
 //驗證輸入長度
 if(document.Form1.AddMessage1_Content.value.length > 1000)
 {
  alert("您輸入的項目詳細介紹超長,最多隻能輸入1000字");
  event.cancelBubble=true;
  event.returnValue=false;
  document.Form1.AddMessage1_Content.focus();
  return false;
 }
 //驗證留言人姓名
 document.Form1.AddMessage1_LeaveMan.value == document.Form1.AddMessage1_LeaveMan.value.Trim();
 if(document.Form1.AddMessage1_LeaveMan.value == "")
 {
  alert("請輸入您的姓名");
  event.cancelBubble=true;
  event.returnValue=false;
  document.Form1.AddMessage1_LeaveMan.focus();
  return false;
 }
 
 
 //驗證手機號碼
 document.Form1.AddMessage1_Mobile.value == document.Form1.AddMessage1_Mobile.value.Trim();
 /*if(document.Form1.AddMessage1_MsgMobile.value == "")
 {
  alert("請輸入手機號碼");
  event.cancelBubble=true;
  event.returnValue=false;
  document.Form1.AddMessage1_MsgMobile.focus();
  return false;
 }*/
 //驗證手機號碼有效性
 /*rege=/^13/d{9}$/;
 if (!rege.test(document.Form1.AddMessage1_MsgMobile.value))
  {
   alert("手機號碼不合法");
   event.cancelBubble=true;
   event.returnValue=false;
   document.Form1.AddMessage1_MsgMobile.focus();
   return false;
  }
  */
 //電話號碼
 document.Form1.AddMessage1_Phone.value == document.Form1.AddMessage1_Phone.value.Trim();
 if(document.Form1.AddMessage1_Phone.value == "")
 {
  alert("請輸入您的電話");
  event.cancelBubble=true;
  event.returnValue=false;
  document.Form1.AddMessage1_Phone.focus();
  return false;
 }else
 {
    if(!document.Form1.AddMessage1_Phone.value.length>7)
    {
      alert("您輸入的電話位元不對！");
  event.cancelBubble=true;
  event.returnValue=false;
  document.Form1.AddMessage1_Phone.focus();
  return false;
    }
 }
 //聯絡地址
 document.Form1.AddMessage1_ContactAddress.value = document.Form1.AddMessage1_ContactAddress.value.Trim(); 
 if(document.Form1.AddMessage1_ContactAddress.value == "")
 {
  alert("請輸入聯絡地址");
  event.cancelBubble=true;
  event.returnValue=false;
  document.Form1.AddMessage1_ContactAddress.focus();
  return false;
 }
 //郵編
 document.Form1.AddMessage1_Postcode.value = document.Form1.AddMessage1_Postcode.value.Trim(); 
 if(document.Form1.AddMessage1_Postcode.value == "")
 {
  alert("請輸入郵編");
  event.cancelBubble=true;
  event.returnValue=false;
  document.Form1.AddMessage1_Postcode.focus();
  return false;
 }
 //QQ
 document.Form1.AddMessage1_QQ.value = document.Form1.AddMessage1_QQ.value.Trim(); 
 //MSN
 document.Form1.AddMessage1_MSN.value = document.Form1.AddMessage1_MSN.value.Trim(); 
 if(document.Form1.AddMessage1_MSN.value == "")
 {
  /*alert("請輸入MSN地址");
  event.cancelBubble=true;
  event.returnValue=false;
  document.Form1.AddMessage1_MsgMSN.focus();
  return false;*/
 }
 else
 {
  rege=/^([a-zA-Z0-9]+[_|/-|/.]?)*[a-zA-Z0-9]+@([a-zA-Z0-9]+[_|/-|/.]?)*[a-zA-Z0-9]+/.[a-zA-Z]{2,3}$/;
  /*if (!rege.test(document.Form1.MSN.value))
  {
   alert("MSN地址不合法");
   event.cancelBubble=true;
   event.returnValue=false;
   document.Form1.MSN.focus();
   return false;
  }*/
 }
 //Email
 document.Form1.AddMessage1_Email.value = document.Form1.AddMessage1_Email.value.Trim(); 

 if(document.Form1.AddMessage1_Email.value == "")
 {
  /*alert("請輸入E_mail地址");
  event.cancelBubble=true;
  event.returnValue=false;
  document.Form1.AddMessage1_Email.focus();
  return false;*/
 }
 else
 {
  rege=/^([a-zA-Z0-9]+[_|/-|/.]?)*[a-zA-Z0-9]+@([a-zA-Z0-9]+[_|/-|/.]?)*[a-zA-Z0-9]+/.[a-zA-Z]{2,3}$/;
  if (!rege.test(document.Form1.AddMessage1_Email.value))
  {
   alert("Email地址不合法");
   event.cancelBubble=true;
   event.returnValue=false;
   document.Form1.AddMessage1_Email.focus();
   return false;
  }
 }
 
}