function CheckEmail(Field) { // there must be >= 1 character before @, so we // start looking at character position 1 // (i.e. second character) var i = 1; var len = Field.value.length; if (len > 50) { window.alert("email地址长度不能超过50位!"); return false; } pos1 = Field.value.indexOf("@"); pos2 = Field.value.indexOf("."); pos3 = Field.value.lastIndexOf("@"); pos4 = Field.value.lastIndexOf("."); //check '@' and '.' is not first or last character if ((pos1 <= 0)||(pos1 == len-1)||(pos2 <= 0)||(pos2 == len-1)) { window.alert("请输入有效的E-mail地址！"); return false; } else { //check @. or .@ if( (pos1 == pos2 - 1) || (pos1 == pos2 + 1) || ( pos1 != pos3 ) //find two @ || ( pos4 < pos3 ) ) //. should behind the '@' { window.alert("请输入有效的E-mail地址！"); return false; } } return true; } function CheckPhone(Field, FieldTitle) { if (Field.value != "") { for (i = 0; i < Field.value.length; i++) { ch = Field.value.charAt(i); if ( (ch < '0' || ch > '9') && ch != '-' && ch != '(' && ch != ')' && ch != '_' && ch != '+' && ch != '.' ) { alert("\"" + FieldTitle + "\"中只能电话号码数字以及(、)、-、_、+、.符号."); Field.focus(); return false; } } } return true; } function Checkshouji(Field, FieldTitle) { if (Field.value != "") { for (i = 0; i < Field.value.length; i++) { ch = Field.value.charAt(i); if ( (ch < '0' || ch > '9') && ch != '-' && ch != '(' && ch != ')' && ch != '_' && ch != '+' && ch != '.' ) { alert("\"" + FieldTitle + "\"中只能手机号码数字以及(、)、-、_、+、.符号."); Field.focus(); return false; } } } return true; } function Checkyoubian(Field, FieldTitle) { if (Field.value != "") { for (i = 0; i < Field.value.length; i++) { ch = Field.value.charAt(i); if ( (ch < '0' || ch > '9') && ch != '-' && ch != '(' && ch != ')' && ch != '_' && ch != '+' && ch != '.' ) { alert("\"" + FieldTitle + "\"中只能写数字"); Field.focus(); return false; } } } return true; }