function check_form(form)
{
  var er_code=0

  var arr_regex= new Array('',
                           /\w+/,
                           /^[\d\(\+)]+/,
                           /^\+?\d{0,4}\s*\-?\s*\(?\d{0,4}\)?[ \-]*\d{3,4}[ ]*\d{3,4}[\/,\d ]*/,
                           /^[\w\_\.]+@[^\.]+\.[a-zA-Z][a-zA-Z\.]*[a-zA-Z]$/,    
                           /^(\d{1,2})-(\d{1,2})-(\d{4})$/,
                           /^[0-9a-zA-Z]{8}-[0-9a-zA-Z]{8}-[0-9a-zA-Z]{8}-[0-9a-zA-Z]{8}/
                           )

   var er_msg = new Array("",
                          "Please enter ",
                          "Please enter phone no. in valid format",
                          "Phone No is not in valid format",
                          "Please check your email address",
                          "Please enter date in dd-mm-yyyy Format",
                          "Enter valid serial no "
                         )

   var chk_offset = new Array()
       chk_offset[0]=1
   var che_offset = new Array(1,4)
   var cht_offset = new Array(1,2,3)
   var dat_offset = new Array(1,5)
   var chs_offset = new Array(1,6)

    for(i=0;i<form.elements.length;i++){
        txt_name=form.elements[i].name
        substr_txtname=txt_name.substring(0,4)
        fieldname=txt_name.substring(11)
        switch(substr_txtname){
        case "ara_":
        case "chk_":
              for(j=0;j<chk_offset.length;j++)
              {
                 var offset_new=chk_offset[j]
                 var regex=new RegExp(arr_regex[offset_new])
                 if(regex.test(form.elements[i].value)==false){
                    er_code=chk_offset[j]
                    break
                 }
              }
              break
        case "cht_":
              for(j=0;j<cht_offset.length;j++)
              {
                 var offset_new=cht_offset[j]
                 var regex=new RegExp(arr_regex[offset_new])
                 if(regex.test(form.elements[i].value)==false){
                    er_code=cht_offset[j]
                    break
                 }
              }
              break
          case "chs_":
              for(j=0;j<chs_offset.length;j++)
              {
                 var offset_new=chs_offset[j]
                 var regex=new RegExp(arr_regex[offset_new])
                 if(regex.test(form.elements[i].value)==false){
                    er_code=chs_offset[j]
                    break
                 }
              }
              break
        case "che_":
              for(j=0;j<che_offset.length;j++)
              {
                 var offset_new=che_offset[j]
                 var regex=new RegExp(arr_regex[offset_new])
                 if(regex.test(form.elements[i].value)==false){
                    er_code=che_offset[j]
                    break
                 }
              }
              break
         case "dat_":
              for(j=0;j<dat_offset.length;j++)
              {
                 var offset_new=dat_offset[j]
                 var regex=new RegExp(arr_regex[offset_new])
                 if(regex.test(form.elements[i].value)==false){
                    er_code=dat_offset[j]
                    break
                 }
              }
              break
        }
          if(er_code!=0){
             if(er_code==1){
                  str_ermsg=er_msg[er_code]+fieldname
                alert(str_ermsg.replace(/_/g," "))
             }else{
                alert(er_msg[er_code])
             }
            form.elements[i].focus()
            form.elements[i].select()
            return false
          }
    }

}